Title of Invention

"SULFUR-CONTAINING OLIGOMERS AND HIGH INDEX POLYURETHANES PREPARED THEREFROM"

Abstract

The present invention provides polythiol oligomer formed by the reaction of at least two or more different dienes and at least one or more dithiol wherein stoichiometric ratio of the sum of the number of equivalents of all polythiols to the sum of the number of equivalents of all dienes used to form said polythiol oligomer is greater than 1.0 : 1.0; and wherein said two or more different dienes comprise (a) at least one non-cyclic diene and at least one cyclic diene; or (b) at least one aromatic ring-containing diene and at least one non-aromatic cyclic diene; or (c) at least one non-aromatic monocyclic diene and at least one non-aromatic polycyclic diene; Sulfur-containing polyurethane of the present invention can be prepared by combining polyisocyanate, polyisothiocyanate, or mixture thereof; the polythiol oligomer described above; and active hydrogen-containing material.

Full Text

SULFUR-CONTAINING OLIGOMERS AND HIGH INDEX POLYURETHANES PREPARED THEREFROM [0001] The present invention relates to sulfur-containing polyurethanes and methods for their preparation. [0002] A number of organic polymeric materials,, such as' plastics, have been developed as alternatives and replacements for glass in applications such as optical lenses, fiber optics, windows and automotive, nautical and aviation transparencies. These polymeric materials can provide advantages relative to glass, including, shatter resistance, lighter weight for a'given application, ease of molding and ease of dying. However, the refractive indices of many polymeric materials are generally lower than that of glass. In ophthalmic applications, the use of a polymeric material having a lower refractive index will require a thicker lens relative to a material having a higher refractive index. A thicker lens is not desirable. [0003] Thus, there is a need in the art to develop a polymeric material having high refractive index and good Abbe Number, impact resistance/strength, and optical transparency. [0004] For the purposes of this specification, unless otherwise indicated, all numbers expressing quantities of ingredients, reaction conditions, and so forth used in the specification and claims are to be understood as being modified in all instances by the term "about." Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. [0005] Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contain certain errors necessarily resulting from the standard deviation found in their respective testing measurements. [0006] The present invention provides polythiol oligomer formed by the reaction of at least two or more different dienes and at least one or more dithiol wherein stoichiometric ratio of the sum of the number of equivalents of all polythiols to the sum of the number of equivalents of all dienes used to form said polythiol oligomer is greater than 1.0 : 1.0. In a non-limiting embodiment, said two or more different dienes can comprise (a) at least one non-cyclic diene and at least one cyclic diene; or (b) at least one aromatic ring-containing diene and at least one non-aromatic cyclic diene; or (c) at least one non-aromatic monocyclic diene and at least one non-aromatic polycyclic diene. [0007] In a non-limiting embodiment, said cyclic diene of (a) can be selected from non-aromatic monocyclic dienes, non-aromatic polycyclic dienes, aromatic ring-containing dienes, and mixtures thereof. In a non-limiting embodiment, said non-aromatic cyclic diene of (b) can be selected from non-aromatic monocyclic dienes, non-aromatic polycyclic dienes, and mixtures thereof. In non-limiting embodiments, said stoichiometric ratio can be from greater than 1.0 : 1.0 to 3.0 : 1.0, or from 1.01 .- 1.0 to 3 .0 : 1.0, or from 1.01 : 1.0 to 2.0 : 1.0, or from 1.05 : 1.0 to 2.0 : 1.0, or from 1.1 : 1.0 to 1.5 : 1.0, or from 1.25 : 1.0 to 1.5 : 1.0. [0008] In a further non-limiting embodiment, polythiol oligomer of the present invention can include polythiol oligomer formed by the reaction of two or more different dienes, one or more dithiol, and optionally trifunctional or higher-functional polythiol, wherein stoichiometric ratio of the sum of the number of equivalents of all polythiols to the sum of the number of equivalents of all dienes used to form said polythiol oligomer is greater than 1-0 : 1.0. [0009] In a non-limiting embodiment, sulfur-containing polyurethane of the present invention can comprise the reaction product of polyisocyanate, polyisothiocyanate, or mixture thereof; polythiol oligomer,- and active hydrogen-containing material. In a non-limiting embodiment, said polythiol oligomer can included polythiol oligomer formed by the reaction of at least two or more different dienes and at least one or more dithiol, wherein stoichiometric ratio of the sum of the number of equivalents of all polythiols to the sum of the number of equivalents of all dienes used to form said polythiol oligomer is greater than 1.0 : l.0. In a further non-limiting embodiment, said active hydrogen-containing material can include at least one material selected from trifunctional or higher-functional polyol, trifunctional or higher-functional polythiol, trifunctional or higher-functional material containing both hydroxyl and SH groups, or mixtures thereof. In a further non-limiting embodiment, said active hydrogen-containing material can further comprise at least one material selected from diol, dithiol, difunctional material including both hydroxyl and SH groups, or mixtures thereof. In a further non-limiting embodiment, said dithiol can include dithiol oligomer. In a further non-limiting embodiment, said stoichiometric ratio can be from 1.1 : 1.0 to 1.5 : 1.0. £0010] In a further non-limiting embodiment polythiol oligomer used to prepare said sulfur-containing polyurethane can include polythiol oligomer formed by the reaction of at least two or more different dienes, at least one or more dithiol, and optionally trifunctional or higher-functional polythiol; wherein the stoichiometric ratio of the sum of the number of equivalents of all polythiols to the sum of the number of equivalents:of all dienes used to form said polythiol oligomer is greater than 1.0 : 1.0. [0011] As used herein and in the claims, when referring to the dienes used in this reaction, the term "different dienes" can include the following non-limiting embodiments: (a) at least one non-cyclic diene and at least one cyclic diene; (b) at least one aromatic ring-containing diene and at least one non-aromatic cyclic diene; or (c) at least one non-aromatic monocyclic diene and at least one non-aromatic polycyclic diene. [0012] In a further non-limiting embodiment, said cyclic diene of (a) can include non-aromatic monocyclic dienes, non-aromatic polycyclic dienes or combinations or mixtures thereof, or aromatic ring-containing dienes, or mixtures thereof. In a further non-limiting embodiment, said non-aromatic cyclic diene of (b) can include non-aromatic monocyclic dienes, non-aromatic polycyclic diene, or combinations or mixtures thereof [0013] As used herein and in the claims, the terms "isocyanate" and "isothiocyanate" refer to materials that are unblocked and capable of forming a covailent bond with a reactive group such as a thiol or hydroxyl functional group. In alternate non-limiting embodiments, the polyisocyanate of the present invention can contain at least two functional groups chosen from isocyanate (NCO), and the polyisothiocyanate can contain at least two functional groups chosen from isothiocyanate (NCS). In another non-limiting embodiment, the polyisothiocyanate of the present invention can contain at least two functional groups chosen from isothiocyanate, and combinations of isocyanate and isothiocyanate functional groups. [0014] In alternate non-limiting embodiments, the sulfur-containing polyurethane of the invention when polymerized can produce a polymerizate having a refractive index of at least 1.55, of at least 1.56, of at least 1.57, or at least 1.58, or at least 1.59, or at least 1.60, or at least 1.61, or at least 1.62, or at least 1.65. In further alternate non-limiting embodiments, the sulfur-containing polyurethane of the invention when polymerized can produce a polymerizate having an Abbe number of at least 30, or at least 32, or at least 34, or at least 35, or at least 36, or at least 38, or at least 39, or at least 40, or at least 44. The refractive index and Abbe number can be determined>by methods known in the art: such as American Standard Test Method (ASTM) Number D 542-00. Further, the refractive index and Abbe number can be determined using various known instruments. In a non-limiting embodiment of the present invention, the refractive index and Abbe number can be measured in accordance with ASTM D 542-00 with the following exceptions: (i) test one to two samples/specimens instead of the minimum of three specimens specified in Section 7.3; and (ii) test the samples unconditioned Instead of conditioning the samples/specimens prior to testing as specified in Section 8.1. Further, in a non-limiting embodiment, an Atago, model DR-M2 Multi- Wavelength Digital Abbe Refractometer can be used to measure the refractive index and Abbe number of the samples/specimens. [0015] In a non-limiting embodiment, sulfur-containing polyurethane of the present invention can be prepared by (a) reacting polyisocyanate and/or polyisothiocyanate; polythiol oligomer formed by the reaction of at least two or more different dienes and at least one or more dithiol, wherein stoichiometric ratio of the sum of the number of equivalents of all polythiols to the sum of the number of equivalents of all dieiies used to form said polythiol oligomer is greater than 1.0 : 1.0; and active hydrogen-containing material including at least one material selected from trifunctional or higher-functional polyol, trifunctional or higher-functional polythiol, trifunctional or higher-functional material containing both hydroxyl and SH groups, or mixtures thereof; to form sulfur-containing polyurethane prepolymer; and (b)reacting said sulfur-containing polyurethane prepolymer with active hydrogen-containing material including at least one material selected from polyol, polythiol, polyfunctional material containing both hydroxyl and SH groups, or mixtures thereof; to form said sulfur-containing polyurethane. [0016] In a further non-limiting embodiment, said active hydrogen-containing material of (a) used to form said sulfur-containing polyurethane prepolymer can further comprise at least one material selected from diol, dithiol, difunctional material including both hydroxyl and SH groups, or mixtures thereof. In a further non-limiting embodiment, said dithiol of (a) can include dithiol oligomer. In a further non-limiting embodiment, said polythiol of (b) can include dithiol oligomer. [0 017] In an alternate non-limiting embodiment, sulfur-containing polyurethane of the present invention can be prepared by (a) reacting polyisocyanate and/or polyisothiocyanate; and polythiol oligomer formed by the reaction of at least two or more different dienes and at least one or more dithiol, wherein stoichiometric ratio of the sum of the number of equivalents of all polythiols to the sum of the number of equivalents of all dienes used to form said polythiol oligomer is greater than 1.0 : 1.0; to form sulfur-containing polyurethane prepolymer; and (b)reacting said sulfur-containing polyurethane prepolymer with active hydrogen-containing material including at least one material selected from trifunctional or higher-functional polyol, trifunctional or higher-functional polythiol, trifunctional or higher-functional material containing both hydroxyl and SH groups, or mixtures thereof; to form said sulfur-containing polyurethane. [0018] In a further nori-limiting embodiment, (a) can further comprise active hydrogen-containing material including at least one material selected from polyol, polythiol, polyfunctional material containing both hydroxyl and SH groups, or mixtures thereof. In a non-limiting embodiment, said polythiol can include dithiol oligomer. In a further noh-limiting embodiment, said active hydrogen-containing material of (b) can further comprise at least one material selected from diol, dithiol, difunctional material including both hydroxyl and SH groups, or mixtures thereof. In a further non-limiting embodiment, said dithiol can include dithiol oligomer. [0019] In alternate non-limiting embodiments, the amount of polyisocyanate and the amount of active hydrogen-containing material used to prepare isocyanate terminated sulfur-containing polyurethane prepolymer can be selected such that the equivalent ratio of (NCO):(SH + OH) can be greater than 1.0:1.0, or at least 2.0.-1.0, or at least 2.5:1, or less than 4.5:1.0, or less than 5.5:1.0. [0020] In alternate non-limiting embodiments, the amount of polyisothiocyanate or mixture of polyisocyanate and polyisothiocyanate and the amount of active hydrogen-containing material used to prepare isothiocyanate or isocyanate/isothiocyanate terminated sulfur-containing polyurethane prepolymer can be selected such that the equivalent ratio of (NCO + NCS) : (SH + OH) can be greater than 1.0:1.0, or at least 2.0:1.0, or at least 2.5:1, or less than 4.5:1.0, or less than 5.5:1.0. [0021] In non-limiting embodiments, the amount of isocyanate terminated sulfur-containing polyurethane prepolymer and the amount of active hydrogen containing materials reacted with said prepolymer to form sulfur-containing polyurethane can be selected such that the equivalent ratio of (OH + SH) : (NCO) is from 1.1 : 1.0 to 0.85 : 1.0, or from 1.1 : 1.0 to 0.90 : 1.0, or from 1.0 : 1.0 to 0.85 : 1.0, or from 1.0 : 1.0 to 0.90 : 1.0. [0022] In non-limiting embodiments, the amount of isothiocyanate or isocyanate/isothiocyanate terminated sulfur-containing polyurethane prepolymer and the amount of active hydrogen containing materials reacted with said prepolymer to form sulfur-containing polyurethane can be selected such that the equivalent ratio of (OH + SH) : (NCS + NCO) is from 1.1 : 1.0 to 0.85 : 1.0, or from 1.1 : 1.0 to 0.90 ; 1.0, or from 1.0 : 1.0 to 0.85 : 1.0, or from 1.0 -. 1.0 to 0.90 : 1.0 . [0023] Polyisocyanates and polyisothiocyanates useful in the preparation of the sulfur-containing polyurethane of the present invention, are numerous and widely varied. Suitable polyisocyanates for use in the present invention can include but are not limited to polymeric and C2-C20 linear, branched, cycloaliphatic and aromatic polyisocyanates. Suitable polyisothiocyanates for use in the present invention can include but are not limited to polymeric and C2-C20 linear, branched, cyclic and aromatic polyisothiocyanates. Non-limiting examples can include polyisocyanates and polyisothiocyanates having backbone linkages chosen from urethane linkages (-NH-C(O)-O-), thiourethane linkages (-NH-C(O)-S-), thiocarbamate linkages (-NH-C(S)-O-}, dithiourethahe linkages (-NH-C(S)-S-) and combinations thereof. [0024] The molecular weight of the polyisocyanate and polyisothiocyanate can vary widely. In alternate non-limiting embodiments, the number average molecular weight (Mn) of each can be at least 100 grams/mole, or at least 150 grams/mole, or less than 15,000 grams/mole, or less than 5000 grams/mole. The number average molecular weight can be determined using known methods. The number average molecular weight values recited herein and the claims were determined by gel permeation chromatography (GPC) using polystyrene standards. [0025] Non-limiting examples of suitable polyisocyanates and polyisothiocyanates can include but are not limited to those described in WO 2004/060951 Al at paragraphs [0014] to [0035], incorporated by reference herein. [0026] In further alternate non-limiting embodiments, the polyisocyanate can include meta-tetramethylxylylene diisocyanate (1,3-bis(1-isocyanato-l-methylethyl-benzene); 3-isocyanato-methyl-3,5,5-trimethyl-cyclohexyl isocyanate ; 4,4 -methylene bis(cyclohexyl isocyanate); meta-xylylene diisocyanate; and mixtures thereof. [0027] In a non-limiting embodiment of the present invention, sulfur-containing polyurethane can be prepared by reacting polyisocyanate and/or polyisothiocyanate and polytihiol oligomer to form sulfur-containing polyurethane prepolymer,- and reacting said sulfur-containing polyurethane prepolymer with active hydrogen-containing material to form said sulfur-containing polyurethane. [0028] In a non-limiting embodiment, polythiol oligomer for use in the present invention can be formed by the reaction of at least two or more different dienes and at least one or more dithiol wherein stoichiometric ratio of the sum of the number of equivalents of all polythiols to the sum of the number of equivalents of all dienes used to form said polythiol oligomer is greater than 1.0 : 1.0. [0029] As used herein and in the claims when referring to the dienes used to prepare said polythiol oligomer, the term "different dienes" can refer to dienes that can be different from one another in any one of a variety of ways. In non-limiting embodiments, the "different diense can be different from one another in one of the following three ways: (a) non-cyclic vs. cyclic,- (b) aromatic vs. non-aromatic ring-containing; or (b) non-aromatic monocyclic vs. non-aromatic polycyclic. In non-limiting embodiments, said at least two or more different dienes can comprise: (a) at least one non-cyclic diene and at least one cyclic diene, wherein non-limiting examples of said cyclic diene can include non-aromatic ring-containing dienes including but not limited to non-aromatic monocyclic dienes, non-aromatic polycyclic dienes or combinations thereof, or aromatic ring-containing dienes, or mixtures thereof; or (b) at least one aromatic ring-containing diene and at least one non-aromatic cyclic diene, wherein non-limiting examples of said non-aromatic cyclic diene can include non-aromatic moncyclic diene, non-aromatic polycyclic, or mixtures thereof; or (c) at least one non-aromatic monocyclic diene and at least one non-aromatic polycyclic diene. [003 0] The two or more different dienes can each be independently chosen from non-cyclic dienes, including straight chain and/or branched aliphatic non-cyclic dienes, non-aromatic ring-containing dienes, including non-aromatic ring-containing dienes wherein the double bonds can be contained within the ring or not contained within the ring or any combination thereof, and wherein said non-aromatic ring-containing dienes can contain non-aromatic monocyclic groups or non-aromatic polycyclic groups or combinations thereof,- aromatic ring-containing dienes,- or heterocyclic ring-containing dienes; or dienes containing any combination of such non-cyclic and/or cyclic groups, and wherein said two or more different dienes can optionally contain thioether, disulfide, polysulfide, sulfone, ester, thioester, carbonate, thiocarbonate, urethane, or thiourethane linkages, or halogen substituents, or combinations thereof; with the proviso that said dienes contain double bonds capable of undergoing reaction with SH groups of polythiol, and forming covalent C-S bonds, and at least two or more of said dienes are different from one another; and the one or more dithiol can each be independently chosen from dithiols containing straight chain and/or branched non-cyclic aliphatic groups, cycloaliphatic groups, aryl groups, aryl-alkyl groups, heterocyclic groups, or combinations or mixtures thereof, and wherein said one or more dithiol can each optionally contain thioether, disulfide, polysulfide, sulfone, ester, thioester, carbonate, thiocarbonate, urethane, or thiourethane: linkages, or halogen substituents, or combinations thereof; and wherein the stoichiometric ratio of the sum of the number of equivalents of all dithiols to the sum of the number of equivalents of all dienes used to form said polythiol oligomer is greater than 1.0 : 1.0. As used herein and in the claims, the term "number of equivalents" refers to the number of moles of a particular diene or polythiol, multiplied by the average number of thiol groups or double bond groups per molecule of said diene or polythiol, respectively. [0031] In non-limiting embodiments, stoichiometric ratio of the sum of the number of equivalants of all polythiols to the sum of the number of equivalents of all dienes used to prepare polythiol oligomer of the present invention can be from greater than 1.0 : 1.0 to 3.0 : 1.0, or from 1.01 : 1.0 to 3.0 : 1.0, or from 1.01 : 1.0 to 2.0 : 1.0, or from 1.05 j 1.0 to 2.0 : 1.0, or from 1.1 : 1.0 to 1.5 : 1.0, or from 1.2S : 1.0 to 1,5 : 1.0. [0032] In a further non-limiting embodiment, the stoichiometric ratio of the sum of the number of equivalents of all polythiols to the sum of the number of equivalents of all dienes used to form said polythiol oligomer can be (n+1) : (n) wherein n can represent an integer from 2 to 3 0 [0033] The reaction mixture that consists of the group of at least two or more different dienes and the group of at least one or more dithiol and the corresponding number of equivalents of each diene and dithiol that is used to prepare the polythiol oligomer can be depicted as shown in Scheme I below: Scheme X. diDn. + d2D2 + . . . + dKDx + tjTi. + . . . + tyTy ► polythiol oligomer; wherein D1 through Dx represent two or more different dienes, x is an integer greater than or equal to 2, that represents the total number of different dienes that are present; di through dx represent the number of equivalents of each corresponding diene; T1 through Ty represent one or more dithiol; and t1 through ty represent the number of equivalents of each corresponding dithiol; and y is an integer greater than or equal to 1 that represents the total number of dithiols present. [0034] In a non-limiting embodiment, a group of at least two or more different dienes and the corresponding number of equivalents of each diene can be described by the term diDi (such as d1D1, through dxDx, as shown in Scheme I above) , wherein Di represents the 1th diene and di represents the number of equivalents of Di, i being can be an integer ranging from 1 to x, wherein x is an integer, greater than or equal to 2, that defines the total number ,of different dienes that are present. Furthermore, the sum of the number of equivalents of all dienes present can be represented by the term d, defined according to Expression (I), (Formula Removed) pression (I) wherein i, x, and di are as defined' above. [0035] Similarly, the group of at lea'st one or more dithiol and the corresponding number of equivalents of each dithiol can be described by the term t-jTj (such as tiTx through t£Ty, as*shown in Scheme I above) , wherein Tj represents the jth dithiol and tj represents the number of equivalents of the corresponding dithiol Tj, j being an integer ranging from 1 to y, where'in y is an integer that defines the total number of dithiols present,, and y has a vallue greater; than or equal to 1. Furthermore, the sum of the number of equivalents of all dithiols present can be represented by the term t, defined according to Expression (II) , (Formula Removed) Expression (II) wherein j, y, and tj are as defined above. [0036] The ratio of the sum of the number of equivalents of all dithiols present to the sum of the number,, of equivalents of all dienes present can be characterized by the term t : d, wherein t and d are as defined above. The ratio t : d can .have values greater than 1:1. In non-limiting embodiments, the ratio- t : d can have values within the range of from greater than 1.0 : 1.0 to 3.0 : 1.0, or from 1.01:1.0 to 3.0 : 1.0, or from 1.01 : 1.0 to 2.0 : 1.0, or from 1.0 5 : 1.0 to 2.0 : 1.0, or from 1.1 .- l.o to 1.5 : 1.0, or from 1.25 : 1.0 to 1.5 : 1.0. E0037] As is known in the art, for a given set of dienes and dithiols, a statistical mixture of oligomer molecules with varying molecular weights are formed during the reaction in which the polythiol oligomer is prepared, where the number average molecular weight of the resulting mixture can be calculated and predicted based upon the molecular weights of the dienes and dithiols, and the relative equivalent ratio or mole ratio of the dienes and dithiols present in the reaction mixture that is used to prepare said polythiol oligomer. As is also known to those skilled in the art, the above parameters can be varied in order to adjust the number average molecular weight of the polythiol oligomer. The following i3 a hypothetical example: if the value of x as defined above is 2, and the value of y is 1; and dienej. has a molecular weight (MW) of 100, diene2 has a molecular weight of 150, dithiol has a molecular weight of 200; and dienex , diene2, and dithiol are present in the following molar amounts: 2 moles of dienex, 4 moles of diene2, and 8 moles of dithiol; then the number average molecular weight (Mn) of the resulting polythiol oligomer is calculated as follows: Mn = { (moleSdienel X MWdienel) + (moleSaiene2 X MWdlene2) + (molesdithiol X MWdithioi) } / m; wherein m is the number of moles of the material that is present in. the smallest molar amount. = {(2 X 100) + (4 X 150) + (8 x 200)} / 2 = 12 0 0 g/mole [0038] In a non-limiting embodiment, the polythiol oligomer can be as depicted in Formula (AA' ) in Scheme II below, produced from the reaction of Dienei and Diene2 with a dithiol; wherein R2/ R4> R6> and R7 can be independently chosen from H, methyl, or ethyl, and Rj. and R3 can be independently chosen from straight chain and/or branched aliphatic non-cyclic moieties, non-aromatic ring-containing moieties, including non-aromatic monocyclic moieties or non-aromatic polycyclic moieties or combinations thereof; aromatic ring- containing moieties; or heterocyclic ring-containing moieties; or moieties containing any combination of such non-cyclic and/or cyclic groups; with the proviso that Dienei and Diene2 are different from one another, and contain double bonds capable of undergoing reaction with SH groups of dithiol, and forming covalent C-S bonds; and wherein R5 can be chosen from divalent groups containing straight chain and/or branched non-cyclic aliphatic groups, cycloaliphatic groups, aryl groups, aryl-alkyl groups, heterocyclic groups, or combinations or mixtures thereof; and wherein R1 R3, and R5 can optionally contain ether, thioether, disulfide, polysulfide, sulfone, ester, thioester, carbonate, thiocarbonate, urethane, or thiourethane linkages, or halogen substituents, or combinations thereof; and n is an integer ranging from 1 to 20. Scheme II (Scheme Removed) [0039] In a second non-limiting embodiment, the polythiol oligomer can be as depicted in Formula (AA') in Scheme III below, produced from the reaction of Diene]. and 5-vinyl-2-norbornene (VWB) with a dithiol; wherein R2 and R4 can be independently chosen from H, methyl, or ethyl, and Rx can be chosen from straight chain and/or branched aliphatic non-cyclic moieties, non-aromatic monocyclic ring-containing moieties; aromatic ring-containing moieties; or heterocyclic ring-containing moieties; or include moieties containing any combination of such non-cyclic and/or cyclic groups; with the proviso that Dienei is different from VNB, and contains double bonds capable of reacting with SH groups of dithiol, and forming covalent C-S bonds; and wherein R3 can be chosen from divalent groups containing straight chain and/or branched non-cyclic aliphatic groups, cycloaliphatic groups, aryl groups, aryl-alkyl groups, heterocyclic groups, or combinations or mixtures thereof, and wherein R1 and R3 can optionally contain ether, thioether. disulfide, polysulfide, sulfone, ester, thioester, carbonate, thiocarbonate, urethane, or thiourethane linkages, or halogen substituents, or combinations thereof; and n is an integer ranging from 1 to 20 . Scheme III (Scheme Removed) [0040] In a third non-limiting embodiment, the polythiol oligomer can be as depicted in Formula (AA'') in Scheme IV below, produced from the reaction of Dienei and 4-vinyl-l-cyclohexene (VCH) with a dithiol; wherein R2 and R4 can be independently chosen from H, methyl, or ethyl, and R1. can be chosen from straight chain and/or branched aliphatic non-cyclic moieties, non-aromatic polycyclic ring-containing moieties; aromatic ring-containing moieties; or heterocyclic ring-containing moieties; or moieties containing any combination of such non-cyclic and/or cyclic groups; with the proviso that Dienex is different from VCH, and contains double bonds capable of reacting with SH group of dithiol, and forming covalent C-S bonds; and wherein R3 can be chosen from divalent groups containing straight chain and/or branched non-cyclic aliphatic groups, cycloaliphatic groups, aryl groups, aryl-alkyl groups, heterocyclic groups, or combinations or mixtures thereof, and wherein R1, and R3 can optionally contain thioether, disulfide, polysulfide, sulfone, ester, thioester, carbonate, thiocarbonate, urethane, or thiourethane linkages, or halogen substituents, or combinations thereof; and n is an integer ranging from 1 to 20. Scheme IV (Scheme Removed) [0041] In a further non-limiting embodiment, the polythiol for use in the present invention can comprise polythiol oligomer formed by the reaction of at least two or more different dienes with at least one or more dithiol, and, optionally, one or more trifunctional or higher functional polythiol; wherein the stoichiometric ratio of the sum of the number of equivalents of all polythiols to the sum of the number of equivalents of all dienes used to prepare said polythiol oligomer is greater than 1.0 : 1.0. [0042] In non-limiting embodiments, said two or more different dienes can each be independently chosen from non-cyclic dienes, including straight chain and/or branched aliphatic-non-cyclic dienes; non-aromatic ring-containing dienes, including non-aromatic ring-containing dienes wherein the double bonds can be contained within the ring or not contained within the ring or any combination thereof, and wherein said non-aromatic ring-containing dienes can contain non-aromatic monocyclic groups or non-aromatic polycyclic groups or combinations thereof; aromatic ring-containing dienes; heterocyclic ring-containing dienes; or dienes containing any combination of such non-cyclic and/or cyclic groups, and wherein said two or more different dienes can optionally contain thioether, disulfide, polysulfide, sulfone, ester, thioester, carbonate, thiocarbonate, urethane, or thiourethane linkages, or halogen substituents, or combinations thereof; with the proviso that said dienes contain double bonds capable of undergoing reaction with SH groups o£ polythiol, and forming covalent C-S bonds, and at least two or more of said dienes are different from one another. In further non-limiting embodiments, the said one or more dithiol can each be independently chosen from dithiols containing straight chain and/or branched non-cyclic aliphatic groups, cycloaliphatic groups, aryl groups, aryl-alkyl groups, heterocyclic groups, or combinations or mixtures thereof, and wherein said one or more dithiol can each optionally contain thioether, disulfide, polysulfide, sulfone, ester, thioester, carbonate, thiocarbonate, urethane, or thiourethane linkages, or halogen substituents, or combinations thereof. In further non-limiting embodiments, the said trifunctional or higher functional polythiol can be chosen from polythiols containing non-cyclic aliphatic groups, cycloaliphatic groups, aryl groups, aryl-alkyl groups, heterocyclic groups, or combinations or mixtures thereof, and wherein said trifunctional or higher functional polythiol can each optionally contain thioether, disulfide, polysulfide, sulfone, ester, thioester, carbonate, thiocarbonate, urethane, or thiourethane linkages, or halogen substituents, or combinations thereof. [0043J Suitable dithiols for use in preparing the polythiol oligomer can be selected from a wide variety known in the art. Non-limiting examples can include those disclosed herein. Further non-limiting examples of suitable dithiols for use in preparing the polythiol oligomer can include but are not limited to 1,2-ethanedithiol, 1,2-propanedithiol, 1,3-propanedithiol, 1,3-butanedithiol, 1,4-butanedithiol, 2,3-butanedithiol, 1,3-pentanedithiol, 1,5-pentanedithiol, 1,6-hexanedithiol, 1,3-dimercapto-3-methylbutane, dipentenedimercaptan, ethylcyclohexyldithiol (ECHDT), 2-mercaptoethylsulfide (DMDS), methyl-substituted 2-mercaptoethylsulfide, dimethyl-substituted 2-mercaptoethylsulfide, 1,8-dimercapto-3,6-dioxaoctane and 1,5-dimercapto-3-oxapentane. In alternate non-limiting embodiments, the dithiol can be 2,5-dimercaptomethyl-l,4-dithiane, ethylene glycol di(2-mercaptoacetate), ethylene glycol di (3-mercaptopropionate), poly (ethylene glycol) di(2-mercaptoacetate), poly(ethylene glycol) di(3-mercaptopropionate), dipentene dimercaptan (DEDM), and mixtures thereof. [00443 Suitable trifunctional and higher-functional polythiols for use in preparing the polythiol oligomer can be selected from a wide variety known in the art. Non-limiting examples can include those disclosed herein. Further non-limiting examples of suitable trifunctional and higher-functional polythiols for use in preparing the polythiol oligomer can include but are not limited to pentaerythritol tetrakis (2-mercaptoacetate), pentaerythritol tetrakis (3-mercaptopropionate), trimethylolpropane tris(2-' mercaptoacetate), trimethylolpropane tris(3-mercaptopropionate),thioglycerol bis(2-mercaptoacetate), trifunctional polythiols with structures depicted in formulas (IV'i), (ivm), (IV'p) , (IV q) disclosed herein, or mixtures thereof. [0045] Suitable dienes for use in preparing the polythiol oligomer can vary widely and can be selected from those known in the art. Non-limiting examples of suitable dienes can include but are not limited to acyclic non-conjugated dienes, acyclic polyvinyl ethers, allyl- and vinyl-acrylates, allyl- and vinyl-methacrylates, diacrylate and dimethacrylate esters of linear diols and dithiols, diacrylate and dimethacrylate esters of poly(alkyleneglycol) diols, monocyclic aliphatic dienes, polycyclic aliphatic dienes, aromatic ring-containing dienes, diallyl and divinyl esters of aromatic ring dicarboxylic acids, and mixtures thereof. [0046] Non-limiting examples of acyclic non-conjugated dienes can include those represented by the following general formula: wherein R can represent C2 to C30 linear branched divalent saturated alkylene radical, or C2 to C30 divalent organic radical containing at least one element selected from the group consisting of sulfur, oxygen and. silicon in addition to carbon and hydrogen atoms. [0047] In alternate non-limiting embodiments, the acyclic non-conjugated dienes can be selected from 1,5-hexadiene, 1,6-heptadiene, 1, 7-octadiene and mixtures thereof. [0048] Non-limiting examples of suitable acyclic polyvinyl ethers can include but are not limited to those represented by structural formula (V ): (Formula Removed) wherein R2 can be C2 to Cs n-alkylene, C2 to C6 branched alkylene group, or --[(CH2 --)p --0--]q --(--CH2 --)r --, m can be a rational number from 0 to 10, p can be an integer from 2 to 6, q can be an integer from 1 to 5 and r can be an integer from 2 to 10. [0049] Xn a non-limiting embodiment, m can be two (2). [0050] Non-limiting examples of suitable polyvinyl ether monomers for use can include divinyl ether monomers, such as but not limited to ethylene glycol divinyl ether, diethylene glycol divinyl ether, triethyleneglycol divinyl ether, and mixtures thereof. [0051] Non-limiting examples of suitable allyl- and vinyl-acrylates and methacrylates can include but are not limited to those represented by the following formulas: (Formula Removed) wherein R1 each independently can be hydrogen or methyl. [0052] In a non-limiting embodiment, the acrylate and methacrylate monomers can include monomers such as but not limited to allyl methacrylate, allyl acrylate and mixtures thereof. [0053] Non-limiting examples of diacrylate and dimethacrylate esters of linear diols can include but are not limited to those represented by the following structural formula: (Formula Removed) wherein R can represent C1 to C30 divalent saturated alkylene radical; branched divalent saturated alkylene radical; or C2 to C3!) divalent organic radical containing at least one element selected from sulfur, oxygen and silicon in addition to carbon and hydrogen atoms; and R2 can represent hydrogen or methyl. [0054] In alternate non-limiting embodiments, the diacrylate and dimethacrylate esters of linear diols can include ethahediol dimethacrylate, 1,3-propanediol diacrylate, 1,3-propanediol dimethacrylate, 1,2-propanediol diacrylate, 1, 2-propanediol dimethacrylate, 1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate, 1, 3 -butanediol diacrylate, 1,3 -butanediol dimethacrylate, 1,2-butanediol diacrylate, 1,2-butanediol dimethacrylate, and mixtures thereof. £0055] Non-limiting examples of diacrylate and dimethacrylate esters of poly (alJcyleneglycol) diols can include -but are not limited to those represented by the following structural .formula: (Formula Removed) wherein R2 can represent hydrogen or methyl and p ,can represent an integer from 1 to 5. [0056] In alternate non-limiting embodiments, the diacrylate and dimethacrylate esters of poly(alkyleneglycbl) diols can include ethyleneuglycol dimethacrylate, ethylene glycol diacrylate, diethylene! glycol dimethacrylate, diethylene glycol diacrylate, and mixtures thereof. [0057] Further non-limiting examples of suitable dienes can include monocyclic aliphatic dienes such as butS; not: limited to those represented by the following structural formula's: ; Y*,(Formula Removed) wherein X and Y each independently can represent C1-10. divalent saturated alkylene radical; or C1-5 divalent saturated alkylene radical, containing at least one element -selected fromjthe group of sulfur, oxygen and silicon in addition to the carbon and hydrogen atoms; and R1 can represent H, or C1-C10 ;alkyl;: and (Formula Removed) wherein X and R1 can be as defined above and R2 can represent C:>-G10 alkenyl. [0058] In alternate non-limiting;.embodiments;, the monocyclic aliphatic dienes can include 1,4-cycloheka.diene, 4-vinyl-l-cyclohexene, dipentene arid .fcerpinene. [0059] Npn-limiting examples of polycyclic aliphatic dienes can include but are not limited to 5-vinyl-2-norbornene; 2,5-norbornacLiene ,• dicyclopentadiene and mixtures thereof. [0060] Non- limiting ...examples of aromatic ring-containing dienes can include but are not limited to those represented by the foilow ing structur al formula: (Formula Removed) wherein ;;R4 can represent hydrogen or methyl. [0061] In alternate non-limiting embodiments,,the aromatic ring-containing dienes can include monomers such as 1,'3-diispropenyl benzene, divinyl benzene and mixtures thereof. [00 62] Non-limiting examples of diallyl esters of aromatic ring dicarbbxylic acids can include but are not limited to those represented by the following structural formula: (Formula Removed) wherein m and n each independently can be an integer from 0 to 5. [0063] In alternate non-limiting embodiments, the diallyl esters of aromatic ring dicarboxylic acids can include o-diallyl phthalate, m-diallyl phthalate, p-diallyl phthalate and mixtures thereof. [0064] In a non-limiting embodiment, reaction of at least one polythiol with two or more different dienes can be carried out in the presence of radical initiator. Suitable free radical initiators for use in the present invention can vary widely and can include those known to one of ordinary skill in the art. Non-limiting examples of radical initiators can include but are not limited to azo or peroxide type free-radical initiators such as azobisalkalenenitriles. In a non-limiting embodiment, the free radical initiator can be azobisalkalenenitrile which is commercially available from DuPont under the trade name VAZO™. In alternate non-limiting embodiments, VAZO-52, VAZO-64, VAZO-67, VAZO-88 and mixtures thereof can be used as free radical initiators. [0065] In a non-limiting embodiment, selection of the free-radical initiator can depend on reaction temperature. In a non-limiting embodiment, the reaction temperature can vary from room temperature to 100°C. In further alternate non-limiting embodiments, Vazo 52 can be used at a temperature of from 50-60 °C, or Vazo 64 or Vazo 67 can be used at a temperature of 60 °C to 75 °C, or Vazo 88 can be used at a temperature of 75-100 °C. [0066] The reaction of at least one polythiol and two or more different dienes can be carried out under a variety of reaction conditions. In alternate non-limiting embodiments, such conditions can depend on the degree of reactivity of the dienes and the desired structure of the resulting polythiol oligomer. [0067] In a non-limiting embodiment, said at least two or more different dienes and said polythiol can be reacted together by forming a mixture of said materials and free radical initiator, and allowing said dienes and polythiol to react. In a further non-limiting embodiment, reaction of said mixture of materials can be carried out with heating of mixture. In a further non-limiting embodiment, polythiol and free radical initiator can be combined together, and resulting mixture can be added in relatively small amounts over a period of time to a mixture of two or more dienes. [0068] In an alternate non-limiting embodiment, two or more different dienes can be reacted with polythiol in a stepwise manner under free radical initiation. In a non-limiting embodiment, a mixture of polythiol, one diene, and optionally free radical initiator can be prepared; the polythiol and diene and optionally free radical initiator can be allowed to react until double bonds are essentially consumed; and then a second diene can be added to the resulting mixture, followed by addition of free radical initiator to the mixture. The resulting mixture then is allowed to react until the double bonds are essentially consumed and a pre-calculated theoretical SH equivalent weight is obtained (e.g., calculated based upon stoichiometry and measured by titration). The reaction time for completion can vary from one hour to five days depending on the reactivity of the dienes used, and reaction temperature can vary widely, depending upn the reactivity of the dienes used and the type and amount of radical initiator that is used. [0069] In non-limiting embodiments, polythiol oligomer can comprise random-type or block-type structure (i.e., random-type or block-type sequencing of repeat units of said polythiol oligomer). [0070] In a non-limiting embodiment, polythiol oligomer with random-type structure; i.e., random sequencing of repeat units, can be prepared by reacting together at least two or more different dienes, polythiol, and free radical initiator. In a non-limiting embodiment, a mixture of said dienes, said polythiol, and free radical initiator can be prepared and allowed to react. In an alternate non-limiting embodiment, a mixture of said polythiol and said free radical initiator can be prepared and added over a period of time to a mixture of said dienes. [0071] In an alternate non-limiting embodiment, polythiol oligomer with block-type structure; i.e., block-type or blocky sequencing of repeat units, can be prepared by reacting at least two or more different dienes, polythiol, and free radical initiator in a stepwise manner. In a non-limiting embodiment, a mixture of polythiol, one diene, and optionally free radical initiator can be prepared; the polythiol and diene and optionally free radical initiator can be allowed to react until double bonds are essentially consumed; and then a second diene and free radical initiator can be added to the resulting mixture; the resulting mixture then is allowed to react until the double bonds are essentially consumed and a pre-calculated theoretical SH equivalent weight is obtained. [0072] In a non-limiting embodiment, the reaction of polythiol with at least two or more different dienes can be carried out in the presence of a catalyst. Suitable catalysts for use in the reaction can vary widely and can be selected from those known in the art. The amount of catalyst used in the reaction of the present invention can vary widely and can depend on the catalyst selected. In a non-limiting embodiment, the amount of catalyst can be present in an amount of from 0.01% by weight to 5% by weight of the reaction mixture. [0073] In a non-limiting embodiment, wherein the mixture of dienes can include acrylic and/or methacrylic monomers, the acrylic and/or methacrylic monomers can be reacted with polythiol in the presence of a base catalyst. Suitable base catalysts for use in this reaction vary widely and can be selected from those known in the art. Non-limiting examples can include but are not limited to tertiary amine bases such as 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and N,N-dimethylbenzylamine. The amount of base catalyst used can vary widely. In a non-limiting embodiment, the base catalyst can be present in an amount of from 0.01 to 5.0% by weight of the reaction mixture. The use of base catalyst in the reaction of the acrylic and/or methacrylic monomers with polythiol can substantially minimize or essentially preclude double bond polymerization. [0074] In a non-limiting embodiment, in order to substantially minimize or essentially preclude double bond polymerization, acrylic and/or methacrylic double bonds can be first reacted with polythiol under basic catalysis conditions and then, electron-rich reactive double bond dienes can be added to the intermediate product and reacted under radical initiation conditions. Non-limiting examples of electron-rich reactive double bond dienes can include materials such as but not limited to vinyl ethers, aliphatic dienes and cycloaliphatic dienes. [0075] In a non-limiting embodiment, polythiol oligomer formed by reacting acrylic and/or methacrylic dienes and polythiol in the presence of base catalyst, followed by reaction with said electron-rich dienes can have block-type copolymer structure (i.e., block-type sequencing of repeat units of said polythiol oligomer). [0076] In an alternate non-limiting embodiment, in order to substantially minimize or essentially preclude double bond polymerization, double bonds of non-(meth)acrylic dienes can first be reacted with dithiol under free-radical initiation conditions (for example, heating in the presence of free radical initiator) and then, dienes having acrylic and/or methacrylic double bonds can be added to the intermediate product and reacted under base catalysis conditions. [0077] In a non-limiting embodiment, polythiol oligomer formed by first reacting non(meth)acrylic dienes and polythiol under free radical initiation conditions, followed by reacting acrylic and/or methacrylic dienes under base catalysis conditions can have block-type copolymer structure (i.e., block-type sequencing of repeat units of said polythiol oligomer) . [007 8] Not intending to be bound by any particular theory, it is believed that as the mixture of polythiol, dienes and radical intiator is heated, the double bonds are at least partially consumed by reaction with the SH groups of the polythiol. The mixture can be heated for a sufficient period of time such that the double bonds are essentially consumed and a pre-calculated theoretical value for SH content is reached. In a non-limiting embodiment, the mixture can be heated for a time period of from 1 hour to 5 days. In another non-limiting embodiment, the mixture can be heated at a temperature of from 40°C to 1Q0°C. [0079] The number average molecular weight (Mn) of the resulting polythiol oligomer can vary widely. The number average molecular weight (Mn) of polythiol oligomer can be predicted based on the stoichiometry of the reaction. In alternate non-limiting embodiments, the M„ of polythiol oligomer can vary from 400 to 10,000 g/mole, or from 1000 to 3000 g/mole. [0080] The viscosity of the resulting polythiol oligomer can vary widely. In alternate non-limiting embodiments, the viscosity can be from 40 cP to 4000 cP at 73°C, or from 40 cP to 2000 cP at 73°C, or from 150 cP to 1500 cP at 73°C. [00 81] In a non-limiting embodiment, vinylcyclohexene (VCH) and 1,5-hexadiene (1,5-HD) can be combined together, and 2-mercaptoethylsulfide (DMDS) and a radical initiator (such as Vazo 52)can be mixed together, and this mixture can be added dropwise to the mixture of dienes at a rate such that a temperature of 60°C is not exceeded. After the addition is completed, the mixture can be heated to maintain a temperature of 60°C until the double bonds are essentially consumed and the pre-calculated theoretical value for SH content is reached. [0082] In alternate non-limiting embodiments, polythiol oligomer can be prepared from the following combinations of dienes and polythiol: (a) 5-vinyl-2-norbornene (VNB), diethylene glycol divinyl ether (DEGDVE)and DMDS; (c) VNB, DEGDVE, BDDVE, DMDS; (d) 1,3-diisopropenylbenzene (DIPEB), DEGDVE and DMDS; (e) DIPEB, VNB and DMDS; (f) DIPEB, 4-vinyl-l-cyclohexene (VCH), DMDS; (g) allylmethacrylate (AM), VNB, and DMDS; (h) VCH, VNB, and DMDS; (i) Limonene(L), VNB and DMDS; (j) Ethylene glycol dimethacrylate (EGDM), VCH and DMDS; (k) Diallylphthalate (DAP), VNB, DMDS; (1) Divinylbenzene(DVB), VNB, DMDS; (m) DVB, VCH, DMDS; and (n) 1,5-HD, VCH, DMDS [0083] In an alternate non-limiting embodiment, the polythiol for use in the present invention can include polythiol oligomer formed by the reaction of at least two or more different dienes and at least one or more dithiol and, optionally, one or more trifunctional or higher functional polythiol, wherein said dienes can be selected such that at least one diene has refractive index of at least 1.52 and at least one other diene has Abbe number of at least 40„ wherein said dienes contain double bonds capable of reacting with SH groups of polythiol, and forming covalent C-S bonds; and wherein the stoichiometric ratio of the sum of the number of equivalents of all polythiols present to the sum of the number of equivalents of all dienes present is greater than 1.0 : 1.0. In a further non-limiting embodiment, the diene with refractive index of at least 1.52 can be selected from dienes containing at least one aromatic ring, and/or dienes containing at least one sulfur-containing substituent, with the proviso that said diene has refractive index of at least 1.52; and the diene with Abbe number of at least 40 can be selected from cyclic or non-cyclic dienes not containing an aromatic ring, with the proviso that said diene has Abbe number of at least 40. In yet a further non-limiting embodiment, the diene with refractive index of at least 1.52 can be selected from diallylphthalate and 1,3-diisopropenyl benzene; and the diene with Abbe number of at least 40 can be selected from 5-vinyl-2-norbornene, 4-vinyl-l-cyclohexene, limonene, diethylene glycol divinyl ether, and allyl methacrylate. [00 84] As is known in the art, the nature of the SH group of polythiols is such that oxidative coupling can occur readily, leading to formation of disulfide linkages. Various oxidizing agents can lead to such oxidative coupling. As is also known in the art, the oxygen in the air can in some cases lead to such oxidative coupling during storage of the polythiol. As is known in the art, it is believed that a possible mechanism for the coupling of thiol groups involves the formation of thiyl radicals, followed by coupling of said thiyl radicals, to form disulfide linkage. As is known in the art, it is also believed that formation of disulfide linkage can occur under conditions that can lead to the formation of thiyl radical, including but not limited to reaction conditions involving free radical initiation. [00853 In a non-limiting embodiment, the polythiol oligomer for use in the present invention can contain disulfide linkages present in the dithiols and/or polythiols used to prepare said polythiol oligomer. In another non-limiting embodiment, the polythiol oligomer for use in the present invention can contain disulfide linkage formed during the synthesis of said polythiol oligomer. In another non-limiting embodiment, the polythiol oligomer for use in the present invention can contain disulfide linkages formed during storage of said polythiol oligomer. [0086] In an alternate non-limiting embodiment, the reaction mixture containing polyisocyanate and polythiol oligomer can include at least one additional active hydrogen-containing material. Active hydrogen-containing materials are varied and known in the art. Non-limiting examples can include hydroxyl-containing materials such as but not limited to polyols,• sulfur-containing materials such as but not limited to hydroxyl functional polysulfides, and SH-containing materials such as but not limited to polythiols; and materials having both hydroxyl and thiol functional groups. [0087] Suitable hydroxyl-containing materials for use in the present invention can include a wide variety of materials known in the art. Non-limiting examples can include but are not limited to polyether polyols, polyester polyols, polycaprolactone polyols, polycarbonate polyols, polyurethane polyols, poly vinyl alcohols, polymers containing hydroxy functional acrylates, polymers containing hydroxy functional methacrylates, polymers containing allyl alcohols and mixtures thereof. [0088] Polyether polyols and methods for their preparation are known to one skilled in the art. Many polyether polyols of various types and molecular weight are commercially available from various manufacturers. Non-limiting examples of polyether polyols can include but are not limited to those described in WO 2004/060951 Al at paragraphs [0038] to [0040], incorporated by reference herein. [0089] A variety of polyester polyols and polycaprolactone polyols suitable for use in the present invention are known in the art. Suitable polyester polyols and polycaprolactone polyols can include but are not limited to those described in WO 2004/060951 at paragraphs [0041] and [0042], respectively, incorporated by reference herein. [0090] Polycarbonate polyols for use in the present invention are varied and known to one skilled in the art. Suitable polycarbonate polyols can include but are not limited to those described in WO 2004/060951 at paragraph [0043]. [0091] Further non-limiting examples of active hydrogen-containing materials can include low molecular weight di-functional and higher functional polyols and mixtures thereof. In a non-limiting embodiment, these low molecular weight materials can have a number average molecular weight of less than 500 grams/mole. In a further non-limiting embodiment', the amount of low molecular weight material chosen can be such to avoid a high degree of cross-linking in the polyurethane. The di-functional polyols typically contain from 2 to 16, or from 2 to 6, or from 2 to 10, carbon atoms. Non-limiting examples of such difunctional polyols can include but are not limited to ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, 1,2-, 1,3- and 1,4-butanediol, 2,2,4-trimefchyl-1,3-pentanediol, 2-methyl-l,3-pentanediol, 1,3- 2,4- and 1,5-pentanediol, 2,5- and 1,6-hexanediol, 2,4-heptanediol, 2-ethyl-1,3-hexanediol, 2,2-dimethyl-1,3-propanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 1,2-bis(hydroxyethyl)-cyclohexane and mixtures thereof. Non-limiting examples of trifunctional or tetrafunctional polyols can include glycerin, tetramethylolmethane, pentaerythritol, trimethylolethane, trimethylolpropane, alkoxylated polyols such as but not limited to ethoxylated trimethylolpropane, propoxylated trimethylolpropane, ethoxylated trimethylolethane; and mixtures thereof. [0092] In a non-limiting embodiment, the active hydrogen-containing material can comprise block polymers including blocks of ethylene oxide-propylene oxide and/or ethylene oxide-butylene oxide. In a non-limiting embodiment, the active hydrogen-containing material can comprise a block copolymer of the following chemical formula:• (Formula Removed) (I") wherein Rj through R6 can each independently represent hydrogen or methyl; a, b, and c can each be independently an integer from 0 to 3 00. wherein a, b and c are chosen such that the number average molecular weight of the polyol does not exceed 32,000 grams/mole, as determined by GPC. In a further non-limiting embodiment, a, b, and c can be chosen such that the number average molecular weight of the polyol does not exceed 10,000 grams/mole, as determined by GPC. In a non-limiting embodiment, a, b, and c can each be independently an integer from 1 to 300. In a non-limiting embodiment, Rl, R2, Rs, and Rs are hydrogen, and R3 and R4 are each independently chosen from hydrogen and methyl, with the proviso that R3 and R4 are different from one another. In another non-limiting embodiment, R3 and R4 are hydrogen, and R1 and R2 are each independently chosen from hydrogen and methyl, with the proviso that R1 and R2 are different from one another, and Rs and R£ are each independently chosen from hydrogen and methyl, with the proviso that R5 and RE are different from one another. £0093] In further alternate non-limiting embodiments, Pluronic R, Pluronic L62D, Tetronic R or Tetronic, which are commercially available from BASF, can be used as active hydrogen-containing material in the present invention. C0094] In alternate non-limiting embodiments, the active hydrogen-containing material for use in the present invention can be chosen from polyether polyols, polyester polyols and polycaprolactone polyols having a number average molecular weight of at least 200 grams/mole, or at least 350 grams/mole, or at least 700 grams/mole, or at least 900 grams/mole; or less than or equal to 3,000 grams/mole, or less than or equal to 5,000 grams/mole, or less than or equal to 10,000 grams/mole, or no less than or equal to 15,000 grams/mole. [0095] Non-limiting examples of suitable polyols for use in the present invention can include straight or branched chain alkane polyols, such as but not limited to those described in WO 2004/060951 at paragraph [0050]at page 17, line 11 to page 18, line 6, incorporated by reference herein, and mixtures thereof. [0096] In a further non-limiting embodiment, the polyol can be a polyurethane prepolymer having two or more hydroxy functional groups. Such polyurethane prepolymers can be prepared from any of the polyols and polyisocyanates previously described herein. In a non-limiting embodiment, the OH:NCO equivalent ratio can be chosen such that essentially no free NCO groups are produced in preparing the polyurethane prepolymer. In alternate non-limiting embodiments, the equivalent ratio of OH to NCO (i.e., isocyanate) present in the polyurethane prepolymer can be an amount of from 2-0 to less than 5.5 OH/1.0 NCO. [0097] In alternate non-limiting embodiments, the polyurethane prepolymer can have a number average molecular weight (Mn) of less than 50,000 grams/mole, or less than 20,000 grams/mole, or less than 10,000 grams/mole, or less than 5,000 grams/mole, or greater than 1,000 grams/mole or greater than 2,000 grams/mole. [0098] In a non-limiting embodiment, the active hydrogen-containing material for use in the present invention can include sulfur-containing materials such as SH-containing materials, such as but not limited to polythiols having at least two thiol groups. Non-limiting examples of suitable polythiols can include but are not limited to aliphatic polythiols, cycloaliphatic polythiols, aromatic polythiols, heterocyclic polythiols, polymeric polythiols, oligomeric polythiols and mixtures thereof. The sulfur-containing active hydrogen-containing material can have linkages including but not limited to ether linkages (-0-), sulfide linkages (-S-), polysulfide linkages {-Sx-, wherein x is at least 2, or from 2 to 4) and combinations of such linkages. As used herein and the claims, the terms "thiol," "thiol group," "mercapto" or "mercapto group" refer to an -SH group which is capable of forming a thiourethane linkage, (i.e., -NH-C(O)-S-) with an isocyanate group or a dithioruethane linkage (i.e., -NH-C(S)-S-) with an isothiocyanate group. [0099] Non-limiting examples of suitable polythiols can include but are not limited to 2,5-dimercaptomethyl-1,4-dithiane, dimercaptoethylsulfide, pentaerythritol tetrakis(3- mercaptopropionate), pentaerythritol tetrakis(2-mercaptoacetate), trimethylolpropane tris(3-mercaptopropionate), trimethylolpropane tris(2-mercaptoacetate), 4-mercaptomethyl-3,6-dithia-l,8-octanedithiol, 4-tert-butyl-l,2-benzenedithiol, 4,4'-thiodibenzenethiol, ethanedithiol, benzenedithiol, ethylene glycol di(2-mercaptoacetate), ethylene glycol di(3-mercaptopropionate), poly(ethylene glycol) di (2-mercaptoacetate) and poly(ethylene glycol) di (3-mercaptopropionate), and mixtures thereof. [00100] The polythiol can be chosen from materials described in WO 2004/060951 Al at paragraphs [0056] to [0060], incorporated by reference herein. The polythiol can be chosen from those previously disclosed, such as but not limited to 2,5-dimercaptomethyl-l,4-dithiane,. In alternate non-limiting embodiments, the sulfur can be in the form of crystalline, colloidal, powder or sublimed sulfur, and can have a purity of at least 95 percent or at least 98 percent. In another non-limiting embodiment, the polythiol oligomer can have disulfide linkages and can include materials such as those described in WO 2004/060951 Al at paragraph [0061], incorporated by reference herein. [00101] As is known in the art, the nature of the SH group of polythiols is such that oxidative coupling can occur readily, leading to formation of disulfide linkages. Various oxidizing agents can lead to such oxidative coupling. As is also known in the art, the oxygen in the air can in some cases lead to such oxidative coupling during storage of the polythiol. As is known in the art, it is believed that a possible mechanism for the coupling of thiol groups involves the formation of thiyl radicals, followed by coupling of said thiyl radicals, to form disulfide linkage. As is known in the art, it is also believed that formation of disulfide linkage can occur under conditions that can lead to the formation of thiyl radical, including but not limited to reaction conditions involving free radical initiation. [00102] In a non-limiting embodiment, the polythiol for use in the present invention can include species containing disulfide linkage formed during storage. [001031 In another non-limiting embodiment, the polythiol for use in the present invention can include species containing disulfide linkage formed during synthesis of said polythiol. In a non-limiting embodiment, the polythiol for use in the present invention, can include those described in WO 2004/060951 Al at paragraphs [0062] to [0093] at page 30, line 31, incorporated by reference herein. [00104] In a non-limiting embodiment, polythiol for use in the present invention can include polythiol oligomer formed by the reaction of dithiol with diene, via the thiol-ene type reaction of the SH groups of said dithiol with double bond groups of said diene. [001051 In a non-limiting embodiment, polythiol for use in the present invention can include at least one oligomeric polythiol as follows: (Formula Removed) wherein R1can be selected from C2 to C6 n-alkylene; C3 to C6 alkylene unsubstituted or substituted wherein substituents can be hydroxyl, methyl, ethyl, methoxy or ethoxy,- or C6 to Ca cycloalkylene; R2 can be selected from C2 to C6 n-alkylene, C2 to Ce branched alkylene, C6 to C8 cycloalkylene, Cs to C10 alkylcycloalkylene or --[(CH2 --)P --0--]q --(--CH2 ~-)r --; m can be a rational number from 0 to 10, n can be an integer from l to 20, p can be an integer from 2 to 6, q can be an integer from 1 to 5, and r can be an integer from 2 to 10. [00106] Various methods of preparing the polythiol of formula (IV f) are described in detail in United States Patent 6,509,418B1, column 4, line 52 through column 8, line 25, which disclosure is herein incorporated by reference. In general, this polythiol can be prepared by combining reactants comprising one or more polyvinyl ether monomer, and one or more polythiol. Useful polyvinyl ether monomers can include but are not limited to divinyl ethers represented by structural formula (V): (Formula Removed) wherein R2 can be selected from C2 to c6 n-alkylene, C2 to C6 branched alkylene, C6 to c8 cycloalkylene, C= to C10 alkylcycloalkylene or --[(CH2 --)p --0--]q --(--CH2 --}r --, m is a rational number ranging from 0 to 10, p is an integer from 2 to 6, q is an integer from 1 to 5 and r is an integer from 2 to 10. [00107] In a non-limiting embodiment, m can be two (2). [00108] Non-limiting examples of suitable polyvinyl ether monomers for use can include divinyl ether monomers, such as but not limited to ethylene glycol divinyl ether, diethylene glycol divinyl ether, butane diol divinyl ether and mixtures thereof. [00109] In alternate non-limiting embodiments, the polyvinyl ether monomer can constitute from 10 to less than 50 mole percent of the reactants used to prepare the polythiol, or from 3 0 to less than 50 mole percent. [00110] The divinyl ether of formula (V) can be reacted with polythiol such as but not limited to dithiol represented by the formula (VI'): (Formula Removed) wherein R1 can be selected from C2 to Ce n-alkylene group; C3 to C6 branched alkylene group, having one or more pendant groups which can include but are not limited to hydroxyl, alkyl such as methyl or ethyl; alkoxy, or C6 to C8 cycloalkylene. [00111] Further non-limiting examples of suitable polythiols for reaction with Formula (V) can include those polythiols represented by Formula 2. herein. £00112] Non-limiting examples of suitable polythiols for reaction with Formula (V) can include but are not limited to dithiols such as 1, 2-ethanedithiol, 1, 2 -propanedithiol, 1, 3-propaneditb.iol, 1,3-butanedithiol, 1,4-butanedithiol, 2,3-butanedithiol, 1,3- pentanedithiol, 1,5-pentanedithiol, 1,6-hexanedithiol, 1,3-dimercapto-3-methylbutane, dipentenedimercaptan, ethylcyclohexyldithiol (ECHDT), dimercaptodiethylsulfide (DMDS), methyl-substituted dimercaptodiethylsulfide, dimethyl-substituted dimercaptodiethylsulfide, dimercaptodioxaoctane, 1,5-dimercapto-3-oxapentane and mixtures thereof. [00113] In a non-limiting embodiment, the polythiol for reaction with Formula (V) can have a number average molecular weight ranging from 90 to 1000 grams/mole, or from 90 to 500 grams/mole. In a further non-limiting embodiment, Che stoichiometric ratio of polythiol to divinyl ether can be less than one equivalent of polyvinyl ether to one equivalent of polythiol. £00114] in a non-limiting embodiment, the polythiol and divinyl ether mixture can further include one or more free radical initiators. Non-limiting examples of suitable free radical initiators can include azo compounds, such as azobis-nitrile compounds such as but not limited to azo(bis)isobutyronitrile (AIBN); organic peroxides such as but not limited to benzoyl peroxide and t-butyl peroxide; inorganic peroxides and similar free-radical generators. [00115] In alternate non-limiting embodiments, the reaction to produce the material represented by Formula (IV'f) can include irradiation with ultraviolet light either with or without a photoinitiator. [00116] In a non-limiting embodiment, the polythiol for use in the present invention can include material represented by the following structural formula and prepared by the following reaction: (Formula Removed) wherein n can be an integer from 1 to 20. [00117] Various methods of preparing the polythiol of formula (IV g) are described in detail in WO 03/042270, page 2, line 16 to page 10, line 7, which disclosure is incorporated herein by reference. In general, the polythiol can have number average molecular weight of from 100 to 3000 grams/mole. The polythiol can be prepared by ultraviolet (UV) initiated free radical polymerization in the presence of suitable photoinitiator. Suitable photoinitiators in usual amounts as known to one skilled in the art can be used for this process. In a non-limiting embodiment, 1-hydroxycyclohexyl phenyl ketone (Irgacure 184) can be used in an amount of from 0.05% to 0.10% by weight, based on the total weight of the polymerizable monomers in the mixture. [00118] In a non-limiting embodiment, the polythiol represented by formula (IVg) can be prepared by reacting "n" moles of allyl sulfide and "n+1" moles of dimercaptodiethylsulfide as shown above. [00119] In a non-limiting embodiment, the polythiol for use in the present invention can include a material represented by the following structural formula and prepared by the following reaction: (Formula Removed) wherein n can be an integer from 1 to 20. [0012 0] Various methods for preparing the polythiol of formula (IVh) are described in detail in WO/01/6S623A1, from page 3, line 19 to page 6, line 11, the disclosure of which is incorporated herein by reference. In general, polythiols can be prepared by reaction of thiol such as dithiol, and aliphatic, ring-containing non-conjugated diene in the presence of radical initiator. Non-limiting examples of suitable thiols can include but are not limited to lower alkylene thiols such as ethanedithiol, vinylcyclohexyldithiol, dicyclopentadienedithiol, dipentene dimercaptan, and hexanedithiol; polyol esters of thioglycolic acid and thiopropionic acid; and mixtures thereof and mixtures thereof. £00121] Non-limiting examples of suitable cyclodienes can include but are not limited to vinylcyclohexene, dipentene, dicyclopentadiene, cyclododecadiene, cyclooctadiene, 2-cyclopenten-1-yl-ether, 5-vinyl-2-norbornene and norbornadiene. [00122] Non-limiting examples of suitable radical initiators for the reaction can include azo or peroxide free radical initiators such as azobisalkylenenitrile which is commercially available from DuPont under the trade name VAZO™. [00123] In a further non-limiting embodiment, "n+1" moles of dimercaptoethylsulfide can be reacted with "n" moles of 4-vinyl-1-cyclohexene, as shown above, in the presence of VAZO-52 radical initiator. [00124] In a non-limiting embodiment, the polythiol for use in the present invention can include a material represented by the following structural formula and reaction scheme: (Scheme Removed) wherein Rx and R3 can each be independently selected from C1 to C6 n-alkylene, C2 to C6 branched alkylene, C6 to CB cycloalkylene, C6 to C10 alkylcycloalkylene, C6 to C8 aryl, C6 to C10 alkyl-aryl, C1-C10 alkyl containing ether linkages or thioether linkages or ester linkages or thioester linkages or combinations thereof, --[(CH2 --)p --X--]q --(--CHZ --)r --, wherein X can be O or S, p can be an integer from 2 to 6, q can be an integer from 1 to 5, r can be an integer from 0 to 10; R2 can be selected from hydrogen or methyl; and n can be an integer from 1 to 20. [00125] In general, the polythiol of formula (IV'j) can be prepared by reacting di(meth)acrylate monomer and one or more polythiols. Non-limiting examples of suitable di(meth)acrylate monomers can vary widely and can include those known in the art, such as but not limited to ethylene glycol di(meth(acrylate, 1,3-butylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 2,3-dimethylpropane 1,3 ~di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, propylene glcol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, tetrapropylene glycol di(meth)acrylate, ethoxylated hexanediol di(meth)acrylate, propoxylated hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, alkoxylated neopentyl glycol di(meth)acrylate, hexylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polybutadiene di(meth)acrylate, thiodiethyleneglycol di(meth)acrylate, trimethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, alkoxylated hexanediol di(meth)acrylate, alkoxyolated neopentyl glycol di(meth)acrylate, pentanediol di(meth)acrylate, cyclohexane dimethanol di(meth)acrylate, ethoxylated bis-phenol A di(meth)acrylate. [00126] Non-limiting examples of suitable polythiols for use as reactants in preparing polythiol of Formula (IV'j) can vary widely and can include those known in the art, such as but not limited to 1,2-eth.anedithiol, l, 2 -propanedithiol, 1,3 -propanedi thiol, 1,3-butanedithiol, 1,4-butanedithiol, 2,3-butanedithiol, 1,3-pentanedithiol, 1,5-pentanedithiol, 1,6-hexanedithiol, 1,3-dimercapto-3-methylbutane, dipentenedimercaptan, ethylcyclohexyldithiol (ECHDT), dimercaptodiethylsulfide (DMDS), methyl-substituted dimercaptodiethylsulfide, dimethyl-substituted dimercaptodiethylsulfide, dimercaptodioxaoctane, 3,6-dioxa,1,8-octanedithiol, 2-mercaptoethyl ether, 1,S-dimercapto-3-oxapentane, 2,5-dimercaptomethyl-l,4-dithiane (DMMD),ethylene glycol di(2-mercaptoacetate), ethylene glycol di(3-mercaptopropionate), and mixtures thereof. [00127] In a non-limiting embodiment, the di(meth)acrylate used to prepare the polythiol of formula (IVj) can be ethylene glycol di (meth) aLcrylate. [00128] In another non-limiting embodiment, the polythiol used to prepare the polythiol of formula (IV'j) can be dimercaptodiethylsulfide (DMDS). [00129] In a non-limiting embodiment, the reaction to produce the polythiol of formula (IV'j) can be carried out in the presence of base catalyst. Suitable base catalysts for use in this reaction can vary widely and can be selected from those known in the art. Non-limiting examples can include but are not limited to tertiary amine bases such as l,8-diazabicyclo[S.4.0]undec-7-ene (DBU) and N,lading thy lbenzyl amine . The amount of base catalyst used can vary widely. In a non-limiting embodiment, base catalyst can be present in an amount of from 0.001 to 5.0% by weight of the reaction mixture. [00130] Not intending to be bound by any particular theory, it is believed that as the mixture of polythiol, di(meth)acrylate monomer, and base catalyst is reacted, the double bonds can be at least partially consumed by reaction with the SH groups of the polythiol. [00131] In a non-limiting embodiment, the mixture can be reacted for a period of time such that the double bonds are substantially consumed and a pre-calculated theoretical value for SH content is achieved. In a non-limiting embodiment, the mixture can be reacted for a time period of from 1 hour to 5 days, in another non-limiting embodiment, the mixture can be reacted at a temperature of from 20 °C to 100 °C. In a further non-limiting embodiment, the mixture can be reacted until a theoretical value for SH content of from 0.5% to 20% is achieved. [00132] The number average molecular weight (Mn) of the resulting polythiol can vary widely. In a non-limiting embodiment, the number average molecular weight (Mn) of polythiol can be determined by the stoichiometry of the reaction. In alternate non-limiting embodiments, the Mn of polythiol can be at least 400 g/mole, or less than or equal to 5000 g/mole, or from 1000 to 3000 g/mole. [00133] In a non-limiting embodiment, the polythiol for use in the present invention can include a material represented by the following structural formula and reaction scheme: (Scheme Removed) wherein Rx and R3 each can be independently selected from C1 to Cs n-alkylene, C2 to Cs branched alkylene, C6 to Ca cycloalkylene, C6 to C10 alkylcycloalkylene, C6 to C8 aryl, C6 to C10 alkyl-aryl, C1-C10, alkyl containing ether linkages or thioether linkages or ester linkages or thioester linkages or combinations thereof, --[(CH2 --)P --X--]q --(--CH2 --)r --/ wherein X can be 0 or S, p can be an integer from 2 to 6, q can be an integer from 1 to 5, r can be an integer from 0 to 10; R2 can be selected from hydrogen or methyl, and n can be an integer from 1 to 20. [00134] In general, the polythiol of formula (IVk) can be prepared by reacting polythio(meth)acrylate monomer, and one or more polythiols. Non-limiting examples of suitable polythio(meth)acrylate monomers can vary widely and can include those known in the art such as but not limited to di(meth)acrylate of 1,2-ethanedithiol including oligomers thereof, di(meth)acrylate of dimercaptodiethyl sulfide (i.e., 2,2'-thioethanedithiol di(meth)acrylate) including oligomers thereof, di(meth)acrylate of 3,6-dioxa-l,8-octanedithiol including oligomers thereof, di(meth)acrylate of 2-mercaptoethyl ether including oligomers thereof, di(meth)acrylate of 4,4'~ thiodibenzenethiol, and mixtures thereof. 100135] The polythio(meth)acrylate monomer can be prepared from polythiol using methods known to those skilled in the art, including but not limited to those methods disclosed in US 4,810,812, US 6,342,571; and WO 03/011925. Non-limiting examples of suitable polythiol for use as reactant(s) in preparing polythiols can include a wide variety of polythiols known in the art, such as but not limited to l,2-ethanedithiol, 1,2-propanedithiol, 1,3-propanedithiol, 1,3-butanedithiol, 1, 4-butanedith.iol, 2,3-butanedithiol, 1,3-pentanedithiol, 1,5-pentanedithiol, 1,6-hexanedithiol, 1,3-dimercapto-3-methylbutane, dipentenedimercaptan, ethylcyclohexyldithiol (ECHDT), dimercaptodiethylsulfide, methyl-substituted dimercaptodiethylsulfide, dimethyl-substituted dimercaptodiethylsulfide, dimercaptodioxaoctane, 3,6-dioxa,1,8-octanedithiol, 2-mercaptoethyl ether, 1,5-dimercapto-3-oxapentane, 2,5-dimercaptomethyl-l,4-dithiane (DMMD),ethylene glycol di(2-mercaptoacetate), ethylene glycol di(3-mercaptopropionate), and mixtures thereof. [00136] In a non-limiting embodiment, the polythio(meth)acrylate used to prepare the polythiol of formula (IV k) can be di(meth)acrylate of dimercaptodiethylsulfide, i.e., 2,2'-thiodiethanethiol dimethacrylate. In another non-limiting embodiment, the polythiol used to prepare the polythiol of formula (IV k) can be dimercaptodiethylsulfide (DMDS). [00137] In a non-limiting embodiment, this reaction can be carried out in the presence of base catalyst. Non-limiting examples of suitable base catalysts for use can vary widely and can be selected from those known in the art. Non-limiting examples can include but are not limited to tertiary amine bases such as 1,8-diazabicyclo[5.4.0]undec~7-ene (DBU) and N,N-dimethylbenzylamine. [00138] The amount of base catalyst used can vary widely. In a non-limiting embodiment, the base catalyst can be present in an amount of from 0.001 to 5.0% by weight of the reaction mixture. In a non-limiting embodiment, the mixture can be reacted for a time period of from 1 hour to 5 days. In another non-limiting embodiment, the mixture can be reacted at a temperature of from 20 °C to 100 °C. In a further non-limiting embodiment, the mixture can be heated until a precalculated theoretical value for SH content of from 0.5% to 20% is achieved. [00139] The number average molecular weight (Mn) of the resulting polythiol can vary widely. In a non-limiting embodiment, the number average molecular weight (Mn) of polythiol can be determined by the stoichiometry of the reaction. In alternate non-limiting embodiments, the Mn of polythiol can be at least 400 g/mole, or less than or equal to SOOOg/mole, or from 1000 to 3000g/mole. [00140] In a non-limiting embodiment, the polythiol for use in the present invention can include a material represented by the following structural formula and reaction: (Formula Removed) wherein Ra can be selected from hydrogen or methyl, and R2 can be selected from C1 to C6 n-alkylene, C2 to C6 branched alkylene, C6 to C8 cycloalkylene, Ce to C10 alkylcycloalkylene, C6 to C8 aryl, C6 to C10 alkyl-aryl, C1-C10 alkyl containing ether linkages or thioether linkages or ester linkages or thioester linkages or combinations thereof,or --[(CH2 --)p --X--]g --(--CH2 --)r --# wherein X can be selected from O or S, p can be an integer from 2 to 6, q can be an integer from 1 to 5, r can be an integer from 0 to 10; and n can be an integer from 1 to 20. [00141] In general, the polythiol of formula (IV1) can be prepared by reacting allyl (meth) acrylate, and one or more polythiols. [00142] Non-limiting examples of suitable polythiols for use as reactant(s) in preparing polythiol of formula (IV1) can include a wide variety of known polythiols such as but not limited to 1,2-ethanedithiol, 1,2-propanedithiol, 1,3-propanedithiol, 1,3-butanedithiol, 1,4-butanedithiol, 2,3-butanedithiol, 1,3-pentanedithiol, 1,5-pentanedithiol, 1,6-hexanedithiol, 1,3-dimercapto-3-methylbutane, dipentenedimercaptan, ethylcyclohexyldithiol (ECHDT), dimercaptodiethylsulfide, methyl-substituted dimercaptodiethylsulfide, dimethyl-substituted dimercaptodiethylsulfide, dimercaptodioxaoctane, 3,6-dioxa,1,8-octanedithiol, 2-mercaptoethyl ether, 1,5-dimercapto-3-oxapentane, 2, 5-ditnercaptomethyl-l,4-dithiane,ethylene glycol di (2-mercaptoacetate), ethylene glycol di(3-mercaptopropionate), and mixtures thereof. [00143] In a non-limiting embodiment, the polythiol used to prepare the polythiol of formula (IV 1) can be dimercaptodiethylsulfide (DMDS)- [00144] In a non-limiting embodiment, the (meth)acrylic double bonds of allyl (meth)acrylate can be first reacted with polythiol in the presence of base catalyst . Non-limiting examples of suitable base catalysts can vary widely and can be selected from those known in the art. Non-limiting examples can include but are not limited to tertiary amine bases such as 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and N,N-dimethylbenzylamine. The amount of base catalyst used can vary widely. In a non-limiting embodiment, base catalyst can be present in an amount of from 0.001 to 5.0% by weight of the reaction mixture. In a non-limiting embodiment, the mixture can be reacted for a time period of from 1 hour to 5 days. In another non-limiting embodiment, the mixture can be reacted at a temperature of from 2 0 °C to 100 °C. In a further non-limiting embodiment, following the reaction of the SH groups of the polythiol with substantially all of the available (meth)acrylate double bonds of the allyl (meth)acrylate, the allyl double bonds can then be reacted with the remaining SH groups in the presence of radical initiator. [0014 5] Not intending to be bound by any particular theory, it is believed that as the mixture is heated, the allyl double bonds can be at least partially consumed by reaction with the remaining SH groups. Non-limiting examples of suitable radical initiators can include but are not limited to azo or peroxide type free-radical initiators such as azobisalkylenenitriles. In a non-limiting embodiment, the free-radical initiator can be azobisalkylenenitrile which is commercially available from DuPont under the trade name VAZO™. In alternate non-limiting embodiments, VAZO-52, VAZO-S4, VAZO-67, or VAZO-88 can be used as radical initiators. [00146] In a non-limiting embodiment, the mixture can be heated for a period of time such that the double bonds are substantially consumed and a desired pre-calculated theoretical value for SH content is achieved. In a non-limiting embodiment, the mixture can be heated for a time period of from 1 hour to 5 days. In another non-limiting embodiment, the mixture can be heated at a temperature of from 40°C to 100°C. In a further non-limiting embodiment, the mixture can be heated until a theoretical value for SH content of from 0.5% to 20% is achieved. [00X47J The number average molecular weight (Mn) of the resulting polythiol can vary widely. In a non-limiting embodiment, the number average molecular weight (Mn) of polythiol can be determined by the stoichiotnetry of the reaction. In alternate non-limiting embodiments, the M„ of polythiol can be at least 400 g/mole, or less than or equal to SOOOg/mole, or from 1000 to 3000g/mole. E001481 In another non-limiting embodiment, trifunctional polythiol for use in the present invention can include a material represented by the following structural formula and reaction scheme: (Scheme Removed) where n can be an integer from 1 to 20. C00149] In a non-limiting embodiment, the polythiol of formula (IV'in) can be prepared by reacting ™xi" moles of 1,2,4-trivinylcyclohexane (TVCH) with "3n" moles of dimercaptodiethylsulfide (DMDS), and heating the mixture in the presence of a suitable free radical initiator, such as but not limited to VAZO 64. [00150] In another non-limiting embodiment, trifunctional polythiol for use in the present invention can include a material represented by the following structural formula and reaction scheme: (Scheme Removed) where n can be an integer from 1 to 20. [00151J In a non-limiting embodiment, the polythiol of formula (IV'p) can be prepared by reacting wn" moles of trjallyl isocyanurate (TAIC) with "3n" moles of dimercaptodiethylsulfide (DMDS), and heating the mixture in the presence of a suitable free radical initiator, such as but not limited to VAZO 52. [00152] In another non-limiting embodiment, trifunctional polythiol for use in the present invention can include a material represented by the following structural formula and reaction scheme: (Scheme Removed) where n can be an integer from 1 to 20. [00153] In a non-limiting embodiment, the polythiol of formula (IV'q) can be prepared by reacting "n" moles of triallyl cyanurate (TAC) with "3a" moles of dimercaptodiethylsulfide (DMDS), and heating the mixture in the presence of a suitable free radical initiator, such as but not limited to VAZO 52. C00154] In another non-limiting embodiment, the polythiol for use in the present invention can include a material represented by the following structural formula: (Formula Removed) wherein n can be an integer from I to 20. [00155] Various methods of preparing tpie polythiol of the formula (IV i) are described in detail in UnitedsStates Patent 5,225,472, from column 2, line 8 to column 5, line 8. [00156] In a non-limiting embodiment, "3n" moles of 1,8-dimercapto-3,6-dioxaooctane (DMDO) can be reacted; with "n" moles of ethyl formate, as shown above, in the presence off anhydrous zinc chloride. [00157] Non-limiting examples of suitable difunctional or trifunctional active hydrogen-containing: materiai|s having both hydroxyl and thiol groups can include but; are not- limited to 2-mercaptoethanol, 3-mercapto-1,2-propanediol, glycferin bis(2-mercaptqacetate) , glycerin bis (3-mercaptqpropi'bnate) , l-hydroxy-4-mercaptocyclohexane, , 1, 3-dimercapto-2-propanbly, 2, 3-ditnercapto-l-propanol, l,2-dimercapto-l,3-butanedibl, trimethy lolpropane bis(2-mercaptoacetate) , trimethylolpropane bis(3-mercaptopropionate) , pentaerythritol mono (2-mercaptoacetate) , pentaerythritol bis(2-mercaptoacetate), pentaerythritol tris (2-mercapto|icetate), pentaerythritol mono(3-mercaptopropionate;) , pentaerythritol bis(3-mercaptopropionate), pentaerythritol trisJ(3-mercaptopropionate), hydroxymethyl-tris (mercaptoethylthiomethyl)me€hahe, , dihydroxyethyl sulfide mono(3-mercaptopropionate, and mixtures tEereof. [001583 In alternate non-limiting embodiments., the active hydrogenrcontaining material can have a number average molecular weight of at least 200 grams/mole, or at Ieastv 400 grams/mole, or at least 700 grams/mole, or at least 900 grams/mole; or less than or equal to 15,000 grams/mole, or less than or equal to 10,000 grams/mole, or less than or equal to 5,000 grams/.mole, or less than or equal to; 2,500 grams/mole. [00159] The sulfur-containing polyurethane of the present invention can be prepared using a variety [00160] In a non-limiting embodiment of the^present invention, polyiaocyanate, polyisothiocyanate or mixtures{thereof; polythiol oligomer; optionally active hydrogen-containing; material; and optionally urethanation catalyst;can be reacted to form sulfur-containing polyurethane prepolymer. In ndn-limitihg embodiments, said active hydrogen-containing materials can include at least one material selected from polyol, polythiol, polyfunctional material containing both hydroxyl and SH groups, or mixtures thereof. In a non-limiting embodiment, said polythiol can include dithiol oligomer. In a further non-limiting embodiment, said active hydrogen-containing material can includeii at leasjt one material selected from trifunctipnal or higher-functicmallipolyol, trifunctional or higher-functional polythiol,trifunctional or higher-functional material containing bb|ih hydroxyl and SH groups, or mixtures thereof. Non-limiting examples of suitable urethanation catalysts can include those disclosed hereing; in a further non-limiting embodiment, said sulfur-containing polyurethane prepolymer can be chain extended (i.e., reacted) with active hydrogen-containing material including at least one material selected from polyol, polythiol, polythiol oligomer, polyfunctoonal material containing both hydroxyl and SH groups, or mixtures thereof, which have been previously disclosed herein, and optionally in the presence of urethanation catalyst; to form su-l'fur-containing polyurethane polymer. In a non-limiting |enibqdiment, said polythiol can include dithiol oligomer. In a further non-limiting embodiment, said active hydrogen-containing material react?edBw±th sulfur-containing polyurethane prepolymer to form sulfur-containing polyurethane can include at least one material; selected from trifunctional or higher-functional polyol, tri'funbtional or higher-functional polythiol, trifunctional or higher-fuffctional material containing both hydroxyl and SH groups, or mixtures thereof. [00161] In a non-limiting embodiment, saidlsulSur-containing polyurethane prepolymer can contain disulfide linkages by virtue of disulfide linkages contained in polythiol and/or polythiol oligomer used to prepare the polyurethane prepolymer. [00162] In another non-limiting embodiment,; pqlyisocyanate, polyisothiocyanate, or mixtures thereof, polythiol' oligomer, active hydrogen-containing material, and optionally urethanation catalyst can be reacted together in a "one pot" process. In a further non-limiting embodiment, said active hydrogen-containing material can include at least one material chosen from-trifunctional or higher-functional polyol, trifunctional or higher-functional polythiol, , trifunctional or higher-functional material containing both hydroxyl and SH groups, or mixtures thereof. In a further non-limiting embodiment, said active hydrogen-containing material can further comprise at least one material selected from diol, dithiol, difunctional material containing both hydroxyl and SH groups, or mixtures thereof. In a non-limiting embodiment, said dithiol can include dithiol oligomer. [00163] In a non-limiting embodiment, the sulfur-containing polyurethane of the present invention can be prepared by combining polyisocyanate and/or polyisothiocyanate, polythiol oligomer, optionally active hydrogen-containing material, and optionally urethanation catalyst, to form sulfur-containing polyurethane prepolymer, and then adding active hydrogen-containing material and optionally urethanation catalyst to the sulfur-containing polyurethane prepolymer, and polymerizing the resulting mixture. In a further non-limiting embodiment, said prepolymer and said active hydrogen-containing material can be degassed under vacuum prior to mixing them and then carrying out the polymerization. Said active hydrogen-containing material can be mixed with the prepolymer using a variety of methods and equipment, such as but not limited to an impeller or extruder. [00164] In another non-limiting embodiment, wherein the sulfur-containing polyurethane can be prepared by a one-pot process, the polyisocyanate and/or polyisothiocyanate, polythiol oligomer, active hydrogen-containing material, and optionally catalyst, can be separately degassed and then combined and mixed, and the resulting mixture can then be polymerized. In another non-limiting embodiment, said polyisocyanate and/or polyisothiocyanate can be mixed and then degassed; and said polythiol oligomer, active hydrogen-containing material, and optionally catalyst, can be mixed and then degassed, the said mixtures can then be mixed together and polymerized. [00165] In another non-limiting embodiment, wherein a lens can be formed, the mixture of polyurethane-forming materials, including sulfur-containing polyurethane prepolymer, active hydrogen-containing materials and optionally urethanation catalyst; or the mixture of polyisocyanate and/or polyisothiocyanate, polythiol oligomer, and active hydrogen-cohta.ining materials and optionally urethanation catalyst , which can be optionally degass;ed, can be introduced into a mold and the mold can, be heated (i.e., using a thermal cure cycle) using a variety of conventional techniques known in the art. The thermal cure cycle can vary depending on the reactivity and molar ratio of the reactants, and the presence of catalyst(s). In a non-limiting embodiment, theithermal cure cycle can include heating the-mixture of said: polyuretnane-forming materials from room temperature to a temgerature of 200°C over a period of from 0.5 hours to 120 hours; or from 8,0 to 150°C for a period of from 5 hours to 72 hours. [00166] In a non-limiting embodiment, a urethanation catalyst can be used in the present invention to enhance the reaction of the polyurethane-forming materials. Suitable urethanation; catalysts can vary and can include those known in the art; for example, suitable urethanation catalysts can include those catalysts that are useful for the formation of urethane by reaction of the,NC0 and OH-containing materials and/or the reaction of the NCO and SH-containing materials. Non-limiting examples of suitable catalysts can be chosen from the group of Lewis bases, Lewis acids and insertion catalysts as described in Ullmann's Encyclopedia of Industrial Chemistry, 5ch Edition, 1992, Volume A21, pp;. 673 to 674. Non-limiting examples can include but are not limited to tin compounds, tertiary amine catalysts, or mixtures, .thereof. In non-limiting embodiments, tin compounds suitable for .use as urethanation catalyst can include stannous salt of an organic acid, such as but not limited to stannous octoate, dibutyl tin dilaurate, dibutyl tin diacetate, dibutyl tin mercaptide, dibutyl tin dimaleate, dimethyl tin diacetate, dimethyl tin dilaurate, and mixtures thereof. Non-limiting examples of tertiary amines suitable for use as urethanation catalyst can include triethylamine, triisopropylamine, dimethyl cyclohexylamine, N,N-dimethylbenzylamine, 1,4-diazabicyclo[2.2.2]octane, and mixtures thereof; and tertiary amines disclosed in United States Patent 5,693,738 at column 10, lines S-38, the disclosure of which is incorporated herein by reference -Alternate non-limiting examples of suitable urethanation catalyst can include tertiary ammonium salts, pholphihes, zinc octoate, ferric acetylacetonate, or suitable bismuth compounds. [00167] In alternate non-limiting embodiments various known additives can be incorporated into the sulfur,-containing polyurethane of the present invention. Such "additives can include but are not limited to light stabilizers, heat stabilizers, antioxidants, ultraviolet light absorbers, mold, release agents, static (non-photochromic) dyes, pigmehtsifand flexibilizing additives, such as but not limited to al:£oxylated phenol benzoates and poly (alkylene glycol) dibenzoates. Non-liimiting examples of anti-yellowing additives can include 3-methyl;-2-butenoi, organo pyrocarbonates, triphenyl phosphite (CAS registry no. 101-02-0), and hindered phenol antioxidants. Such additivesi can be present in an amount such that the additive constitutes less than 10 ;percent by weight, or less than 5 percent by weight,; or less§ than 3 percent by weight, based on the total weight of the |prepolymer. In alternate non-limiting embodiments, the aforementioned optional additives can be mixed with the polyisocyanate and/or pplyisbtriiocyanate. In a further non-limiting embodiment, the optional,radditives; can be mixed with active hydrogen-containing material. [001683 In a non-limiting embodiment, the resulting sulfur-containing polyurethane of the present invention when at least partially cured can be solid and essentially transparent such that it is suitable for optical or ophthalmic applications. In alternate non-limiting embodiments, the sulfur-containing polyurethane can have a refractive index of at least 1.55, or at least 1.56, or at least 1.57, or at least 1.58, or at least: 1.59,, or .at least 1.60, or at least 1.62, or at least 1.65. In further alternate non-limiting embodiments, the sulfur-containing polyurethane can have an Abbe number of at least 30, or at least 32, orlat ;least; 35, or at least 38, or at least 39, or at least 40, or at least 44. [00169] In a non-limiting embodiment, the sulfur-containing polyurethane when polymerized and at least par;tia«lsly cured can demonstrate good impact resistance/strength. Impact resistance can be measured using a variety of conventional methods known to one skilled in the art. In a non-limiting embpdiment, the impact resistance is measured using the Impact Energy Test which consists of testing a flat sheet sample of polymerizate having a thickness of 3mm, and cut into a square piece approximately 4cm x 4cm. Said flat sheet sample of polymerizate is supported on a flat O-ring which is attached to top of the pedestal of a steel holder, as defined below. Said O-ring is constructed of neoprene having a hardness of 40 +_ 5 Shore A durometer, a minimum tensile strength of 8.3 MPa, and a minimum ultimate elongation of 400 percent, and has an inner diameter of 25 mm, an outer diameter of 31 mm, and a thickness of 2.3 mm. Said steel holder consists of a steel base, with a mass of approximately 12 kg, and a steel pedestal affixed to said steel base. The shape of said steel pedestal is approximated by the solid shape which would result from adjoining onto the top of a cylinder, having an outer diameter of 75 mm and a height of 10 mm, the frustum of a right circular cone, having a bottom diameter of 75 mm, a top diameter of 25 mm, and a height of 8 mm, wherein the center of said frustum coincides with the center of said cylinder. The bottom of said steel pedestal is affixed to said steel base, and the neoprene O-ring is affixed to the top of the steel pedestal, with the center of said O-ring coinciding with the center of the steel pedestal. The flat sheet sample of polymerizate is set on top of the O-ring with the center of said flat sheet sample coinciding with the center of said O-ring. The Impact Energy Test is carried out by dropping steel balls of increasing weight from a distance of 50 inches (1.27 meters) onto the center of the flat sheet sample. The sheet is determined to have passed the test if the sheet does not fracture. The sheet is determined to have failed the test when the sheet fractures. As used herein, the term "fracture" refers to a crack through the entire thickness of the sheet into two or more separate pieces, or detachment of one or more pieces of material from the backside of the sheet (i.e., the side of the sheet opposite' the side of impact). The impact strength of the sheet is reported as the impact energy that corresponds to the highest level (i.e., largest ball) at which the sheet passes the test, and it is calculated acording to the following formula: E=mgd [00170] Wherein E represent impact energy in Joules (J), m represents mass of the ball in kilograms (kg), g represents acceleration due to gravity (i.e., 9.806S5 m/sec2) and? d represents the distance of the ball drop in meters (i.e., 1.27 m). In an alternate non-limiting embodiment, using, the Impact Energy Test as described herein, the impact strength can be at least 1.0 Joule, or at least 2.0 Joules, or at least 4.95 Joules. [00171] In another non-limiting emobidment, the sulfur-containing polyurethane of the present invention when at least partially cured can have low density. In alternate non-i'imiting^embodiinente, the density can be at least 1.0, or at least; 1.1 g/cm3, or less than 1.45, or less than 1.4, or less than 1.3, or less than 1.25, or less than 1.2 g/cm3, or from 1.0 to 1.2 grams/tim3, or from 1.0 to 1.25 grams/cm3, or from 1.0 to 1.3 grams/cm3, or from 1.0 to 1.4 grams/cm3, or from 1.0 to less than 1.45 grams/cm3. In a non-limiting embodiment, the density is measured using a DensiTEGH instrument manufactured by Tech Pro, Incorporated-in accordance with ASTM D297. [00172] Solid articles that can be prepared using the sulfur-containing polyuurethane of the present invention include but are not limited to optical lenses, such as piano and ophthalmic lenses, sun lenses, windows, automotive transparencies, such as windshields, sidelights and backlights, and aircraft transparencies. £00173] In a non-limiting embodiment, the sulfur-containing polyurethane polymerizate of the present invention can be used to prepare phbtochromic articles, such as lenses. In a further embodiment, the polymerizate can be transparent to that portion of the electromagnetic spectrum which activates the photochromic substance(s), i.e., that wavelength of ultraviolet (UV) light that produces the colored or open form of the photochromic substance and that portion of the visible spectrum that includes the absorption maximum wavelength of the photochromic substance in its UV activated form, i.e., the open form. [00174] A wide variety of photochromic substance's can be used in the present invention. Suitable photochromic substances, suitable amounts thereof, and methods of incorporation into the polymerizate are described in WO 2004/060951 Al at [00151] to [00l'61] , incorporated herein by reference. 100175] In another embodiment, the photochromic substance can be added to the sulfur-containing polyurethane prior to polymerizing and/or cast curing the material. In this embodiment, the photochromic substance used can be chosen such that it is resistant to potentially adverse interactions with, for example, the isocyanate, isothiocyante groups present. Such adverse interactions can result in deactivation of the photochromic substance, for example, by trapping them in either an open or closed form. [00176] Further non-limiting examples of suitable photochromic substances for use in the present invention can include photochromic pigments and organic photochromic substances encapsulated in metal oxides such as those disclosed in U.S. patents 4,166,043 and 4,367,170; organic photochromic substances encapsulated in an organic polymerizate such as those disclosed in U.S. Patent 4,931,220. EXAMPLES [00177] In the following examples, unless otherwise stated, the Infrared spectra were measured on Mattsoh Sirius 100 FT-IR apparatus,- the refractive index and Abbe' number were measured on a multiple wavelength Abbe Refractometer Model DR-M2 manufactured by ATAGO Go., Ltd.; the refractive index and Abbe number of liquids were measured in accordance with ASTM-D1218; the.,refractive index and Abbe number of solids were measured in accordance with ASTM-D542; the refractive index (e-line) was measured-rat a temperature of 20°C; and the viscosity was measured using a .Brookfiel'd CAP 2000 + Viscometer. [00178] The NCO concentration of the prepplymer (Component A) was determined by reaction with an excess of n-diButylamihe (DBA) to form the corresponding urea followed by titration of the unreacted DBA with HCl in accordance with ASTM-2572-97. [00179] REAGENTS 1. Tetrahydrofuran (THF) , reagent) grade. 2. 80/20 THF/propylene glycol (PG) mix. This solution was preparedJiin-labi by mixing 0.8 L PG with 3.2 Liters of THE in 4 Loiter bottle. 3. DBA certified ACS. 4. DBA/THF solution. 150 mL of dibutylamine (DBA) was combined with 750'mL tetrahydrofuran (THE); it was mixed well and transfered to an amber bottle. 5. Hydrochloric acid, concentrated. AGS certified. 6. Isopropanol, technical grade. 7. Alcoholic hydrochloric acid, 0.2N. 75-ml of concentrated hydrochloric .acid was slowly added to a 4-liter bottle of technical grade isopropanol, while stirring with a magnetic stirrer. It was mixed for ,a minimum of 3 0 minutes. This solution was standardized using Tris hydroxy1 methyl amino methane (THAM) as follows: into a glass 100-mL beaker, was weighed approximately 0.6 g THAM primary standard to the nearest 0.1 mg and the weight was recorded. 100-mL DI water was added and:.'mixed *to dissolve and titrated with the .prepared' alcoholic HC1. This procedure was repeated a minimum of one time and the values averaged using the calculation below. (Standard wt., grams) Normality HCL = ;_ (mLs HCl) (|6.123|L4^ [00180J EQUIPMENT 1. Polyethylene beakers, 200-niL, .Falcon specimen breakers. No. 354020. 2. Polyethylene lids for abqve^ falcon No. 354017. 3 . Magnetic stirrer and sfiirringaifars. 4. Brinkmann dosimeter for disperising or 10-mL pipet. 5. Autotitrator equipped with pH electrode. S. 25-mL, 50-mL dispensers for solvents or 25-mL and 50-mL pipets. [00181] PROCEDURE- 1. Blank determination: Into a 220-mL^polyethylene beaker was added 50 mL THF, followed by 10.0 mli DBA/THF solution. THe solution was capped and allowed to mix with magnetic -stirrJlrig for 5 minutes. 50 mL of the 80/J20 THF/PG mix was added and titrated using the standardized alcoholic HC1 solution and this volume was .recorded. This procedure was repeated and these values averaged for use as the blank,value. 2. In a polyethylene beaker was .weighecl 1.0 gram of the prepolymer sample, and this weight was recorded to the nearest 0 .,1 mg. 50 mL THF was added, the sample was capped and alilowed to dissolve with magnetic stirring. 3. 10.0 mL DBA/THF solution ;was added, the sample was capped and allowed to react with stirring for 15 minutes. 4. 50 mL 80/20 THF/PG solution was added. 5. The beaker was placedjon the titratpr and the titration was startedX This .procedure was repeated. [001821 CALCULATIONS - (mis Blank - mis Sample) x (Normal*!ty| HC1) x (4.2 018) %NCO = Sample weight', g (Sample wt., grams) x. (1/000;) IEW •Si - Wit'■ -VV*t (mis Blank - mis Sample) x (Normality HC1) IEW = Isocyanate Equivalent Weight [00183] The SH groups within the product were determined using the following procedure. A sample size (0 .lg) of the; product was combined with 50 mL of tetrahydrofuran (THF)/propylene; glycol (80/20) solution and stirred at room terriperature until the sample was substantially dissolved. While stirring 25.0 mL of 0.1 N iodine solution (commercially obtained from Aldriich 31, 8898-1) was added to the mixture and allowed to react for; a time period of 5 to 10 minutes. To this mixture was added 2.0 mL concentrated HC1. The mixture was titrated potentiometrically with 0.1 N sodium thiosulfate in the millivolt (mV) mode. The resul ting volume of titrant is represented as "mLs Sample" in the bellow equation. A blank value was initially obtained by titrating -25.0 mL of iodine (including 1 mL of concentrated hydrochloric iacid) with sodium thiosulfate in the same manner as conducted wiith the product sample. This resulting volume of titrant is represented as "mLs Blank" in the below equation. %SH = (mLsBlank -.. mLsSample) (KTormality Hais2O3')i(3rf307) = 13.4 sample weight, g EXAMPLE q - Synthesis of;«.dithiol oligomeatfromlrDMDS/iyGH^, 2:1 mole ratio (ET.-l) [00184] Charged into a 1-liter 4-necked flask equipped with a mechanical stirrer, thermometer and two gas passing adapters (one for inlet and one for outlet), was dimercaptodiethyl suifide (DMDS) (888.53g, 5.758 moles). The flask was flushed with dry nitrogen and 4-vinyl-l-cyclohexene (VGH) (311.47g, 2.879 moles), was added with stirring; during a time period of 2 hours and 15 minutes. The reaction temperature increased from room temperature to?62°C after 1 hr of addition. Following addition of the VCH, the temperature was 3 7°C. The reaction mixture was then heated to a temperature of S0°C, and five 0.25g-portions of free radical initiator Vazo-52 (2,2'-azobis(2,4-dimethylpentanenitrile) obtained- from DuPont) were added. Eeich portion was added after an interval of one ihour. The reaction mixture was evacuated at 60°C/4-5mm Hg for one ihour to yield 1.2 kg (yield: 100%) of colorless liquid with the -following properties: viscosity of 300 cps @ 25°C, refractive index of 1.597, Abbe number of 39 and SH groups content of 15.9%, SHEW of 208 g/equivalent. Examples 2: Synthesis of .-{block-type dithiol oliigomer from PT-1 and DIPEB, ,2:1 mole ratio (PT-2) [00185] Into a 0.5-liter, 3-necked flask equipped with a mechanical stirrer and thermometer were charged 131.4 g {0.317 moles) of PT-1. To the mixture was then added|at once 25.1 g (0.159 moles) of 1,3-diisopropenylbenzene (DIPEB) and the temperature was increased to 65°C. Two 0.03 g-portions of free radical initiator AIBN (2 , 2'-azobis (2.-methyl-propionitrile)ji) were Sdded. Each of the two portions was added after an interval of two hours. The temperature was maintained at 65°C for another 2 :hours and then double bond analysis (IR spectroscopy) and SH analysis were conducted. The results showed completions of the {reaction. The reaction product (156.5 g, 100% yield) was a clear viscous liquid having a viscosity of 596. cP at 73°C, refractive index of 1.613, Abbe number of 37 and SHEW of 539 g/equrvalent:. Example 3 • Synthesis, of block-,type dithiol oligomer froma DMDS, sDEPEB and DEGDVE (PT-3) [00186] Into a 1-liter, 3-necked f lask equipped with? a mechanical stirrer and thermometer was charged 617.20 g (4.00 moles) of 2-mercaptoethyl sulfide (DMDS). To the DMDS was added dropwise 316.50 g (2.00 moles) of, 1,3-diisopropenylbenzene (DI;FEB) at a rate which allowed the temperature of the mixture to be maintained at less than 65°C. Following addition of all of the 1,31-diisopropenylbenzene, the temperature was maintained at 65°C for ani;additional 30 minutes. Five 0.25g-portions of free radical initiator Vazo-52 were added. Each of the five portions was added after an interval of one hour. Following completion of the reaction, analysis for the presence of double bonds was conducted and showed no dbuble bonds were present. To the mixture was then added 158.0 g (1.0; mole) of diethyleneglycol divinyl ether (DEGDVE), and two 0.25 g-portions of free radical initiator AIBN were added. Each of the two portions of AIBN was added after an interval of two hours. The temperature of the nixture was maintained at 65°C for an additional 2 hours, and then the double bond analysis and SH analysis were conducted. The results showed completion of the reaction. The reaction product (1088 g, 100% yield) was clear viscous liquid having a viscosity of 300 cP at 73°C, refractive, index of 1.603, Abbe number of 37 and SHEW of 540 g/equivalent. Example 4; Synthesis of polythiol oligomer from three equivalents DMDS and one equivalent Triallyl Isocyanurate (TAIC) (PT-4) [00187] Into a 1-liter 3-necked flask equipped; with a mechanical stirrer and thermometer were charged 462.90 grams of 2-mercaptoethyl sulfide (DMDS) (3.0 moles) and 249.27 grams of triallyl isocyanurate (TAIC) (1.00 mole). The mixture was heated to 60°C and then three 0.17 g-portions of free radical initiator Vazo-52 were added at 2 hour intervals. The mixture was stirred and maintained at a temperature of 60°C for a total of 8 hours. A double bond analysis showed no presence of allyl double bonds. The reaction product (712.17 g, 100% yield) was a clear liquid having a viscosity of 445 cP at 73°C, refractive index of 1.609, Abbe number of 38 and SHEW of 248 g/equivalent. EXAMPLE 5 - Synthesis of dithiol oligomer from DMDS/VNB, 2:1 mole ratio (PT-5) [00188] 308 grams of DMDS (2 moles) were charged to a glass jar and the contents were heated to a temperature of 60°C. To the jar was slowly added 120 grams of VNB (1 mole) with mixing. The addition rate was adjusted such that the temperature of the mixture did not exceed 70°C. Once the addition of VNB was completed, stirring of the mixture was continued at 60°C for additional 1 hour. After that time to the mixture were added five 0.04 gram portions of VAZO 52 (one portion added once every hour). The 'mixture was then stirred at a temperature of 60°C for an additional 3 hours, after which time the product was titrated and found to have an SH equivalent weight of 214 g/equivalent. Analysis for the presence of double bonds was conducted and showed no double bonds were present. The viscosity was 56 cps at 73°C, the refractive index was 1.609, and the Abbe number was 41. EXAMPLE 6 - Synthesis of block-type dithiol oligqmer from PT-5 and Ethylene Glycol Dimethacrylate (EGDM), 2:1 mole ratio (PT-6) [00189] At ambient temperature, 134.0 g of Dithiol Oligomer described in Example 5 (PT-5) (0.313 moles) and 30.8 g EGDM (0.156 moles) were charged to a glass jar and mixed. 0.015 g 1,8-Diazabicyclo[5.4.0Jundec-7-ene (DBU) were added to the mixture. Slight increase of the temperature of the mixture was observed, up to 3 6°C initially, then the temperature went back to room temperature. The mixture was stirred at room temperature for 16 hours after which time the product was titrated and found to have an SH equivalent weight of 516 g/equivalent. The viscosity at 73°C was 284 cps, the refractive index was 1.594, and the Abbe number was 42. EXAMPLE 7 - Synthesis of dithiol oligomer from DMDS/DIPEB 2:1 mole ratio (PT-7) [00190] 524.6g of DMDS (3.4 moles) was charged to a glass jar, and the contents were heated to a temperature of 60°C. To the jar was slowly added 269 g of DIPEB (1.7 moles) with mixing at a rate that kept the temperature below 60°C. Once the addition of DIPEB was completed, the jar was placed in an oven heated to 60°C for 2 hours. The jar was then removed from the oven; 0.1 g VAZO 52 was dissolved into the contents of the jar; and the jar was returned to the oven at 60°C for a period of 20 hours . The sample of the resulting mixture was titrated for SH equivalents and was found to have an equivalent weight of 145 g/equivalent. 0.1 g VAZO 52 was dissolved into the reaction mixture, which was then returned to the oven at 60°C. Over a time period of 8 hours, the reaction mixture was kept in the 60 °C oven, and two more additions of 0.2 g VAZO 52 were made. After 17 hours, the resulting sample was titrated, giving an SH equivalent weight of 238 g/equivalent. The viscosity of the material at 25°C was 490 cps. The refractive index of the product was 1.615, and the Abbe number was 34. EXAMPLE 8 - Synthesis of block-type dithiol oligomer from PT-7 and VNB, 2;1 mole ratio (PT-8) [00X91] At ambient temperature, 285.6 g.of dithiol oligomer described in Example 7 (PT-7), (0.6 moles) and 36.1 g VNB (0.3 moles) were charged to a glass jar and mixed. The mixture was put in an oven at 62°C for 1 hour. Then three 0.1 g portions of free radical initiator VAZO 52 were added into the mixture every three hours and the jar was subsecpiently placed in an oven heated to 62°C. After the last addition of radical initiator the mixture was kept in the oven at 62°C for an additional 10.0 hours. The mixture was removed from the oven, and the resulting sample was titrated for SH equivalents and had an equivalent weight of 454 g/equivalent. An additional 0.1 g VAZO 52 was then added to the mixture, and the mixture was returned to the oven for 24 hours. After this time the mixture was removed from the oven and the equivalent weight of the resulting material was titrated and showed SH equivalent weight 543 g/equivalent. IR analysis showed no presence of double bonds. The viscosity at 73°C was 459 cps, the refractive index was 1.617, and the Abbe number was 3 6. Example 9: Polyurethane prepolymer from PT-2 and Desmodur W (PUP-1) £00192] Into a glass jar were charged under nitrogen pillow 48.30 g (0.0484 moles) of PT-2 and 53.75 g (0.2051 moles) of 4,4'-methylenebis(cyclohexyl isocyanate), which was obtained from Bayer Corp. under the trade name Desmodur W. The mixture was heated to a temperature of 70°C and homogenized. 0.050 g (500 ppm) of N,N-dimethyl cyclohexylamine catalyst (Polycat 8, obtained from Air Products and Chemicals, Inc.) was added and the mixture was stirred at a temperature of 70°C for 2 hours. The SH analysis was conducted and showed consumption of SH groups and completion of the reaction. The polythiourethane prepolymer (102 g, 100% yield) was a clear viscous liquid and had NCO content of 11.00%, viscosity of 2838 cP at 73°C, refractive index of 1.571 and Abbe number of 43. Example 10: Polyurethane polymer from PUP-1 (PU-1). [00193] Mixed together were 40 g (0.105 NCO eq;) of PUP-1 and 1 drop of dibutyltin dilaurate (DBTDL) catalyst. The mixture was degassed at a temperature of 80°C under vacuum for 4 hours. Mixed together were 22.62 g (0.0912 SH eq.) of PT-4 and 1 drop of Polycat 8. This mixture was degassed at a temperature of 80°C under vacuum for 2 hours. The two mixtures were then combined and mixed at a (Table Removed) to clear viscous liquid and had NCO content of 12.20!%, viscosity of 1774 cps at 73°C, refractive index of 1.557 and Abbe number of 43. [00196] The invention has been described with reference to non-limiting embodiments. Obvious modifications and alterations can occur to others upon reading and understanding the detailed description. It is intended that the invention be construed as including all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof. We claim: 1. Polythiol oligomer formed by the reaction of two or more different dienes and one or more dithiol wherein stoichiometric ratio of the sum of the number of equivalents of all polythiols to the sum of the number of equivalents of all dienes used to form said polythiol oligomer is greater than 1.0 : 1.0, and wherein said two or more different dienes comprise (a) at least one non-cyclic diene and at least one cyclic diene; or (b) at least one aromatic ring-containing diene and at least one non-aromatic cyclic diene; or (c) at least one non-aromatic monocyclic diene and at least one non-aromatic polycyclic diene. 2 . The polythiol oligomer of claim 1(a) wherein said cyclic diene is selected from non-aromatic monocyclic dienes, non-aromatic polycyclic dienes, aromatic ring-containing dienes, and mixtures thereof. 3. The polythiol oligomer of claim 1(b) wherein said non-aromatic cyclic diene is selected from non-aromatic monocyclic dienes, non-aromatic polycyclic dienes, and mixtures thereof. 4 . The polythiol oligomer of claim 1 wherein said stoichiometric ratio is from 1.1 : 1.0 to 1.5 .- 1.0. 5. The polythiol oligomer of claim l further comprising trifunctional or higher-functional polythiol. 6. A sulfur-containing polyurethane comprising the reaction product of polyisocyanate, polyisothiocyanate, or mixture thereof; polythiol oligomer formed by the reaction of two or more different dienes and one or more dithiol, wherein stoichiometric ratio of the sum of the number of equivalents of all polythiols to the sum of the number of equivalents of all dienes used to form said polythiol oligomer is greater than 1.0 : 1.0; and active hydrogen-containing material including at least one material selected from trifunctional or higher-functional polyol, trifunctional or higher-functional polythiol, trifunctional or higher-functional material containing both hydroxyl and SH groups, or mixtures thereof. The sulfur-containing polyurethane of claim 6 wherein said two or more different dienes comprises at least one non-cyclic diene and at least one cyclic diene. The sulfur-containing polyurethane of claim 6 wherein said two or more different dienes comprises at least one aromatic ring-containing diene and at least one non-aromatic cyclic diene. The sulfur-containing polyurethane of claim 6 wherein said two or more different dienes comprises at least one non-aromatic monocyclic diene and at least one non-aromatic polycyclic diene. The sulfur-containing polyurethane of claim S wherein said polythiol oligomer further comprises trifunctional or higher-functional polythiol. The sulfur-containing polyurethane of claim 6 wherein said active hydrogen-containing material further comprises at least one material selected from diol, dithiol, difunctional material containing both hydroxyl and SH groups, or mixtures thereof. The sulfur-containing polyurethane of claim 11 wherein said dithiol includes dithiol oligomer. The sulfur-containing polyurethane of claim 6 having a refractive index of at least 1.55 and an Abbe number of at least 30, when polymerized. The sulfur-containing polyurethane of claim 6 prepared by: (a) reacting polyisocyanate, polyisothiocyanate, or mixture thereof; polythiol oligomer formed by the reaction of two or more different dienes and one or more dithiol, wherein stoichiometric ratio of the sum of the number of equivalents of all polythiols to the sum of the number of equivalents of all dienes used to form said polythiol oligomer is greater than 1.0 : 1.0; and active hydrogen-containing material including at least one material selected from trifunctional or higher-functional polyol, trifunctional or higher-functional polythiol, trifunctional or higher-functional material containing both hydroxyl and SH groups, or mixtures thereof, to form sulfur-containing polyurethane prepolymer; and (b) reacting said sulfur-containing polyurethane prepolymer with active hydrogen-containing material including at least one material selected from polyol, polythiol, polyfunctional material containing both hydroxyl and SH groups, or mixtures thereof. The sulfur-containing polyurethane of claim 14 wherein said active hydrogen-containing material of (a) further comprises at least one material selected from diol, dithiol, difunctional material containing both hydroxyl and SH groups, or mixtures thereof. The sulfur-containing polyurethane of claim 6 prepared by: (a) reacting polyisocyanate, polyisothiocyanate, or mixture thereof; and polythiol oligomer formed by the reaction of two or more different dienes and one or more dithiol, wherein stoichiometric ratio of sura of number of equivalents of all polythiols to sum of number of equivalents of all dienes used to form said polythiol oligomer is greater than 1.0 : 1.0-; to form sulfur-containing polyurethane prepolymer; and (b) reacting said sulfur-containing polyurethane prepolymer with active hydrogen-containing material including at least one material selected from trifunctional or higher-functional polyol, trifunctional or higher-functional polythiol, trifunctional or higher-functional material containing both hydroxyl and SH groups, or mixtures thereof. The sulfur-containing polyurethane of claim 16 wherein (a) further comprises active hydrogen-containing material including at least one material selected from polyol/ polythiol, polyfunctional material containing both hydroxy1 and SH groups, or mixtures thereof. 18. The sulfur-containing polyurethane of claim 14 wherein the amount of said polyisocyanate, the amount of said polythiol oligomer, and the amount of said active hydrogen-containing are selected such that the equivalent ratio of (NCO) : (SH + OH) is from 2.0 : 1.0 to 5.5 : 1.0. 19. The sulfur-containing polyurethane of claim 14 wherein the amount of said sulfur-containing polyurethane prepolymer and the amount of said active hydrogen-containing of (b) to form sulfur-containing polyurethane are selected such that the equivalent ratio of (OH + SH) : (NCO) is from 1.1 : 1.0 to 0.85 : 1.0 20. The sulfur-containing polyurethane of claim 16 wherein the amount of said polyisocyanate, and the amount of said polythiol oligomer are selected such that the equivalent ratio of (NCO) : (SH ) is from 2.0 : 1.0 to 5.5 : 1.0. 21. The sulfur-containing polyurethane of claim 16 wherein the amount of said sulfur-containing polyurethane prepolymer and the amount of said active hydrogen-containing material of (b) to form sulfur-containing polyurethane are selected such that the equivalent ratio of (OH + SH) : (NCO) is from 1.1 : 1.0 to 0.85 : 1.0 22. A method of preparing sulfur-containing polyurethane comprising: (a) reacting polyisocyanate, polyisothiocyanate, or mixture thereof; polythiol oligomer formed by the reaction of two or more different dienes and one or more dithiol, wherein stoichiometric ratio of the sum of the number of equivalents of all polythiols to the sum of the number of equivalents of all dienes used to form said polythiol oligomer is greater than 1.0 : 1.0; and active hydrogen-containing material including at least one material selected from -trifunctional or higher-functional polyol, trifunctional or higher-functional polythiol, trifunctional or higher-functional material containing both hydroxyl and SH groups, or mixtures thereof, to form sulfur-containing polyurethane prepolymer; and (b) reacting said sulfur-containing polyurethane prepolymer with active hydrogen-containing material including at least one material selected from polyol, polythiol, polyfunctional material containing both hydroxyl and SH groups, or mixtures thereof, to form said sulfur-containing polyurethane. Method of claim 22 wherein said active hydrogen-containing material of (a) further comprises at least one material selected from diol, dithiol, difunctional material containing both hydroxyl and SH groups, or mixtures thereof. Method of claim 22 wherein said polythiol of (b) includes dithiol oligomer. Method of preparing sulfur-containing polyurethane comprising: (a) reacting polyisocyanate, polyisothiocyanate, or mixture thereof; and polythiol oligomer formed by the reaction of two or more different dienes and one or more dithiol, wherein stoichiometric ratio of sum of number of equivalents of all polythiols to sum of number of equivalents of all dienes used to form said polythiol oligomer is greater than 1.0 : 1.0; to form sulfur-containing polyurethane prepolymer; and (b) reacting said sulfur-containing polyurethane prepolymer with active hydrogen-containing material including at least one material selected from trifunctional or higher-functional polyol, trifunctional or higher-functional polythiol, trifunctional or higher-functional material containing both hydroxyl and SH groups, or mixtures thereof, to form said sulfur-containing polyurethane. 26. Method of claim 25 wherein a) further comprises active hydrogen-containing material including at least one material selected from polyol, polythiol, polyfunctional material containing both hydroxyl and SH groups, or mixtures thereof. 27. Method of claim 25 wherein said active hydrogen-containing material of (b) further comprises at least one material selected from diol, dithiol, difunctional material containing both hydroxyl and SH groups, or mixtures thereof. 28. A method of preparing sulfur-containing polyurethane compris ing react ing: (a) polyisocyanate, polyisothiocyanate, or mixture thereof; (b) polythiol oligomer formed by the reaction of two or more different dienes and one or more dithiol, wherein stoichiometric ratio of the sum of the number of equivalents of all polythiols to the sum of the number of equivalents of all dienes used to form said polythiol oligomer is greater than 1.0 : 1.0; and (c) active hydrogen-containing material including at least one material selected from trifunctional or higher-functional polyol, trifunctional or higher-functional polythiol, trifunctional or higher functional material containing both hydroxyl and SH groups,-in a. one-pot process. 29. Method of claim 28 wherein (c) further comprises at least one material chosen from diol, dithiol, difunctional material containing both hydroxyl and SH groups, or mixtures thereof. 30. The sulfur-containing polyurethane of claim 6 wherein said trifunctional or higher functional polythiol includes at least one material s«ilected from pentaerytiirdtol tetrakis(2-mercaptoacetate), pentaerythritol tetrakis(3- mercaptopropionate), and materials represented by the following structural formulas: (Formula Removed) wherein n is an integer ! from 1 |fco?i20 (Formula Removed) wherein n is an integer from, lSjto, 20. : (Formula Removed) wherein nis an.integerfrom 1 to 20. 31. An optical article comprising a,.sulfur-containing polyurethane, wherein said sulfur-containing polyurethane comprises the reaction product of polyisocyanate, polyispthiocyanate, or mixture thereof; -jpolythiol oligoiner formed by the reaction of two or more different dienes and one or more dithiol, wherein stoichiometric ratio of the sum of the number of equivalents, of allpolytHiols to the sum of the number of equivalents pf all dienes need to form said polyfchiol oligomer- is gteater than 1.0 : 1.0; and .active hydrogen-containing material including ac leaat one materiel selected!, from trifuactional ox higher--functional polyol, trifunctional or higher-functiottal poiythiol, crifunctianal ox higher-functional material, containing liocia. hydroxy! and SH groups, or mixtures thereof. 32. The optical article of claim 31, cbnpsrieing an ophthalmic lens. 33. The optical article of claim 31 whas'xein it comprising a. polymerized Eubatrate, and at least a photochromic amount of a photochromAc euostsanoe. 34. The optical article of claim 33 wb.eurei.il said photochromic subotance, ia imbibed into eaid. substrate. 35. The optical article of claim 33 vfaegrein tsoid substiraba. ia coated with a ooafcing composicion comprising at least A photochromic amount o£ a photochroraia substance. 36. A avlfur-containiag polyuretbaxie comprising the reaction product of polyiaocyaaate, polyisothiocyanatce, oar mixture thereof; polythiol oligomer- formed lay ehe reaction, of two or more different: dieoea and one or more dithiol, w'ixex&in Stoichiometric ratio of tlje sum of the number of . equlvsOLenta of all polyfchiola to the sum of tha number of equivalents of all dienee used to Conn 0a id polythiol oligomer is greater than x.o * 1.0/ -laod wctivie faydrogeni-* containing material including at laaet one material selected from trifuacfcional or hiajbefc--functional, polyol -trifuncfcional or hlgtaer-functiojaal poiythiol, trifuncfcional or higher-functional material containing both, hydroxy1 and BH group*, or mixture* thereof; wherein eaid erilJEur-containing polyuretban* contain* dl-oulf.ldc linkage. 37. A sulfur-conlaining polyurcthane as claimed in any one of claims 6-21,30 end 36 substantially as herein described. 38. A method of preparing sulfur-comaimtig polyurcthane as claimed in any one of claims 22-29 substantially as herein described.

Documents:

4460-delnp-2008-1-Correspondence Others-(20-03-2013).pdf

4460-delnp-2008-1-Correspondence Others-(21-03-2013).pdf

4460-delnp-2008-1-Form-13-(15-10-2012).pdf

4460-delnp-2008-1-Form-3-(20-03-2013).pdf

4460-delnp-2008-1-GPA-(20-03-2013).pdf

4460-delnp-2008-1-Petition-137-(20-03-2013).pdf

4460-delnp-2008-abstract.pdf

4460-delnp-2008-assignment.pdf

4460-delnp-2008-Claims-(15-10-2012).pdf

4460-delnp-2008-claims.pdf

4460-delnp-2008-Correspondence Others-(01-06-2012).pdf

4460-delnp-2008-Correspondence Others-(12-03-2013).pdf

4460-delnp-2008-Correspondence Others-(20-03-2013).pdf

4460-delnp-2008-Correspondence Others-(21-03-2013).pdf

4460-delnp-2008-Correspondence Others-(22-05-2013).pdf

4460-delnp-2008-Correspondence-Others-(03-05-2013).pdf

4460-delnp-2008-Correspondence-Others-(15-10-2012).pdf

4460-delnp-2008-Correspondence-Others-(20-09-2012).pdf

4460-delnp-2008-correspondence-others.pdf

4460-delnp-2008-description (complete).pdf

4460-DELNP-2008-Form-1.pdf

4460-DELNP-2008-Form-2.pdf

4460-delnp-2008-Form-3-(20-09-2012).pdf

4460-DELNP-2008-Form-3.pdf

4460-DELNP-2008-Form-5.pdf

4460-DELNP-2008-PCT-101.pdf

4460-DELNP-2008-PCT-210.pdf

4460-delnp-2008-pct-304.pdf