Title of Invention

POLYOXYMETHYLENE (POM)/THERMOPLASTIC POLYURETHANE (TPU) BLEND NANOCOMPOSITES

Abstract The present invention relates to melt mixing of Polyoxymethylene(POM)/Thermoplastic Polyurethane (TPU) blends and intercalated nanofiller organically modified with various quaternary alkyl ammonium surfactants to form nanocomposite blend. These nanocomposite blend are found to exhibit significantly improved impact strength while retaining the tensile strength and modulus and flexural strength and modulus of POM. Impact strength increases to the tune of 215% as compared with the virgin POM matrix and to about 34% as compared to the optimized POM/TPU blend matrix of ratio 65:35 with just 5% loading of C30B nanoclay, organically modified with methyl, tallow, bis-2-hydroxy ethyl quaternary ammonium intercalant. A similar increase in tensile strength and modulus and flexural strength and modulus of the nanocomposite blend to the tune of 65% and 32.36% and 66.16% and 48.53% was observed. Incorporation of hexadecylammonium modified Na-MMT (OMMT) also increased the impact strength of POM/TPU blend matrix modestly to 180.40 J/m at 5 wt% loading. Tensile strength of the blend also increased with the addition of this nanoclay by a factor of 53%, and was almost comparable to the POM matrix. Tensile Modulus of POM/TPU blend also reached to a same value, form 907.42 to 1109 MPa, a much more modest reduction than expected with the incorporation of only TPU in the POM matrix. Flexural strength and modulus of the blend matrix increased to the tune of 41% and 36.1% respectively. WAXD patterns of the blend nanocomposites displayed exfoliated nanomorphology in C30B blend nanocomposites with intercalated structure in the OMMT blend nanocomposite system. TEM micrographs also confirmed improved exfoliation as well as intercalation in C30B blend nanocomposite system.
Full Text 4. DESCRIPTION
This invention relates to nanocomposites from at least one filler of nanometer range which has been
organically modified with various quaternary alkyl amine and alkyl ammonium surfactants. These
organically modified nanoclays are meltmixed with Polyoxymethylene (POM)-Thermoplastic Polyurethane
(TPU) blend of an optimised ratio of 65:35 to increase the impact strength while retaining the tensile
strength and modulus and flexural strength and modulus of POM.
Nanocomposites are polymer systems containing inorganic filler of nanometer range. Some of these are
disclosed in US patent Nos. 6060549, 6103817, 5883173, 5576372, 5576373, 5665185. These materials
blend a nanoclay with polymer to produce a composite with better physical and mechanical properties
than their conventionally filled counterparts, at a lower nanoclay loading.
Nanoclay used in the polymer nanocomposites is based on the smectite class of aluminium silicate clays,
a common representative of which is montmorillonite. Naturally occurring montmorillonite constitutes a 2:1
layered silicate with a central octahedral aluminate structure surrounded on either side with a tetrahedral
silicate structure. Iron or magnesium occasionally replaces the aluminium atom rendering an overall
negative charge which is counter balanced by the inorganic cations residing between the sheets holding
them together. Cation exchange reactions between interlayer inorganic cations and organic cations
increases the intergallery spacing in the silicate sheets, improves compatibility between the fillers and the
matrix thereby resulting in exfoliation. Although naturally occurring and synthetic variations of this basic
mineral structure can be used to prepare nanocomposites, significant property improvements can be
achieved by altering the surface chemistry of clays through cation exchange reactions of interlayer
inorganic cations such as Na sup. + or Ca sup. + with alkyl amine/ammonium cations.
Property improvement is mainly due to the capability of the layers to expand (intercalate) or to completely
separate from each other (exfoliation). This creates an enlarged surface of the filler material and an
enlarged boundary surface with the matrix polymer. To achieve intercalation or exfoliation when
producing polymer nanocomposites, the nanoclays (layered silicates) are modified by cation exchange
with organic compounds and thus made organophilic. They are also referred to as organoclays.
Exfoliated structure of the organoclay provides large surface area with high aspect ratio of the order of 50
to 2000. This results in significant improvement in strength and modulus in polymers.
Working organically intercalated nanoclays into polymers by in-situ polymerization or melt compounding
has been described in several patent documents and is mostly associated with an improvement of the
mechanical and barrier properties as well as thermal stability [U.S. Pat. No. 4,739,007, WO0034180].

Polyoxymethylene (POM or polyacetal) is a polymer whose physical properties include excellent tribology,
hardness, moderate toughness and ability to crystallize rapidly. POM is one of the last major engineering
polymers to be highly impact modified because only a few of the available rubber type materials are
sufficiently compatible to disperse in the melt into sufficiently small particles that then adhere sufficiently
in the solid state to allow stress transfer across the rubber-matrix interface to improve its impact
resistance.
Polyoxymethylenes have good mechanical properties and are therefore used in many application sectors,
either as a constituent of engineering components or else as cladding elements, and the mechanical
property profile of the polyoxymethylenes here can be further improved via admixture of certain other
polymers. By way of example, thermoplastic polyurethanes are admixed with a polyoxymethylene in order
to obtain polymer blends with improved toughness characteristics. Examples of these blends are known
from German Patent Application DE-OS 37 03 232 and U.S. Pat. No. 4,5517,319.
The present report purportedly reports preparation of a POM-TPU blend nanocomposite using various
organically modified nanoclays. This document also reports the improved impact strength of POM in a
nanocomposite blend while retaining the other mechanical properties viz. tensile strength its modulus and
flexural strength its modulus in the system. The nanocomposite blend has been prepared using a melt
blending technique wherein all the ingredients have been compounded in a single step.
The following disclosure may be relevant to various aspects of the present invention and may be briefly
summarized as follows:
Table I illustrates Mechanical properties of POM/TPU blends at various weight % of TPU
Table II depicts Mechanical Properties of nanocomposite blends at POM:TPU ratio of 65:35
FIG. 1 a, b illustrates the SEM micrographs of POM/TPU blends at POM:TPU blend ratio of 65:35
and 50:50.
FIG. 2 a, b, c displays the WAXD patterns of all the nanoclays; Cloisite 30B, OMMT and Na-MMT.
Fig. 3 a, b, c WAXD patterns of nanocomposite blend prepared at POM:TPU ratio of 65:35 using
various organically modified clays (OMMT, Cloisite 30 B, Na-MMT).
Fig. 4 a, b, c TEM Micrographs of nanocomposite blend prepared at POM:TPU ratio of 65:35 using
various organically modified clays (OMMT, Cloisite 30 B, Na-MMT).
The present inventors worked to develop a method of improving the mechanical strength of a
nanocomposite blend. In doing so, we found that a nanocomposite prepared by the incorporation of an
exfoliated/intercalated clay within a POM blend matrix having high impact strength, such as POM/TPU,
POM blended with a thermoplastic elastomer preferably TPU, increases the impact strength of POM while
retaining its tensile and flexural properties.


The nanocomposite blend composition of the present invention is characterized by comprising a POM
matrix resin (a); an intercalated nanoclay from one or more materials selected from i) montmorillonite,
bentonite, kaolinite, mica, hectorite, fluorohectorite, saponite, beidelite, nontronite, stevensite, vermiculite,
hallosite, volkonskoite, suconite, magadite, and kenyalite; ii) the organic material preferably having a
functional group selected from quaternary alkyl ammonium, phosphonium, maleate succinate acrylate,
benzylic hydrogen, a quaternary alkyl amine (b) and TPU (c).
a) Polyoxymethylenes (POM) that can be used are in particular homo- or copolymers which encompass
oxymethylene units. Preferred polyoxymethylenes are unbranched and have at least 50 mol %, preferably
above 80 mol %, particularly preferably above 90 mol %, content of oxymethylene units (-CH.sub.2-O--).
The polymers are obtainable via polymerization of formaldehyde monomers or of cyclic formaldehyde
oligomers, e.g. trioxane or tetraoxane, and, if appropriate, of suitable comonomers such as cyclic ethers
and cyclic acetals, and linear polyacetals, or derivatives of these; preferably cyclic ethers having 2 to 4
carbon atoms or cyclic acetals having 3 to 5 carbon atoms. Preferred comonomers are ethylene oxide,
propylene 1,2-oxide, butylene 1,2-oxide, butylene 1,3-oxide, 1,3-dioxane, 1,3-dioxolane, and 1,3-
dioxepan, and linear oligo- or polyformals, e.g. polydioxolane or polydioxepan.
Component b) Intercalated nanoclay
The intercalated clay used in the nanocomposite comprises organic intercalated clay. The organic content
of the intercalated clay is preferably 1 to 45 wt %. The nanoclay is a natural sodium montmorillonite,
hectorite, bentonite, or synthetic mica with a cation exchange capacity of 60 to 150 mval/100 g.
Layered silicates with a cation exchange capacity of at least 50, preferably 60 to 150 mval/100 g are
preferred. The alkaline or earth alkaline metals that can be exchanged in these swellable layered silicates
are replaced fully or in part by onium ammonium, phosphonium, or sulfoniun ions in an ion.exchange
reaction. Swellable layered silicates in which 50 to 200% of the replaceable inorganic cations are
replaced by organic cations are particularly preferred.
Cationic nitrogen compounds suitable for intercalation are alkylammonium ions such as lauryl ammonium,
myristyl ammonium, palmityl ammonium. Other preferred cationic nitrogen compounds are quaternary
ammonium/amine compounds such as distearyldimethyl ammoniumchloride, methyl benzyl di-
hydrogenated tallow ammonium chloride, octadecyl amine and dimethyldistearylbenzyl
ammoniumchloride.
It is preferred that all nitrogen-containing intercalation components are used in protonated form. All water-
soluble organic and inorganic acids are suitable for protonation. Mineral acids such as hydrochloric acid,


sulfuric acid, nitric acid and phosphoric acid, as well as acetic acid, formic acid, oxalic acid, and citric acid
are preferred.
Examples of those nanoclays, are sodium montmorillonite, Na-MMT (unmodified having CEC
92.6meq/100g clay), cloisite 20A (modified by 2MBHT: dimethyl, dihydrogenated tallow, quaternary
ammonium having CEC of 95meq/100g clay), cloisite 15A (modified by 2MBHT:dimethyl dihydrogenated
tallow quaternary ammonium with CEC 125meq/100g clay), cloisite 30B (modified by MT2EtOT methyl,
tallow, bis-2-hydroxymethyl, quaternary ammonium and CEC of 90 meq / 100g clay) are commercially
available from Southern clay Products Inc, USA.
The layered silicates can be present in the polymer matrix as particles on the micro scale, but given
suitable processing it is however the aim that the layered silicates of the polymer matrix are present
intercalated or in exfoliated state, i.e. as individual layers which are embedded in the polymer matrix
(nano scale).
c) Thermoplastic Polyurethane (TPU)
Examples of thermoplastic elastomers that can be used are thermoplastic polyesters (TPE), thermoplastic
polyamide (TPA), and particularly preferably thermoplastic polyurethanes (TPU). Particular preference is
given to thermoplastic polyurethanes of Elastollan.RTM. type (Elastogran), in particular Elastollan.RTM.
B85A, Elastollan.RTM. SP853, or Elastollan.RTM. G2902. Among the thermoplastic polyurethanes are in
particular also polyurethane rubbers which also contain polyester segments and/or polyether segments,
alongside polyurethane segments. It is preferable to use pellets composed of thermoplastic elastomer
whose average particle diameter is from 50 .mu.m to 1000 .mu.m, particularly preferably from 200 .mu.m
to 700 .mu.m (micropelletized thermoplastic elastomer).
The nanocomposite blend according to the invention has improved performance characteristics and cost
effective as follows:
1. Impact resistance POM as well as the blend matrix is improved significantly with the incorporation of
organically modified nanoclays.
2. Better-exfoliated structure within the blend matrix was obtained with the use of organic surfactant
methyl, tallow, bis-2-hydroxyethyl, quaternary ammonium as intercalative agent in the modification of
the nanoclay, Na-MMT.
3. The flexural and tensile properties of the POM/TPU blend matrix improved considerably with the
addition of organically modified nanoclay.
The process for organic treatment of the nanoclays and the invention is explained in greater detail with
reference to the examples below, to which however it is not limited:


EXAMPLE 1
One untreated and two organically treated clay particles are utilized in the examples of the present
invention. Naturally occurring Cloisite.RTM.Na.sup.+ (Na-MMT) available from Southern Clay Products with
a cation exchange capacity of 92.6 meq/100 grams of clay has been used as the untreated clay. Na-MMT
was organically modified in the laboratory by ion exchange with hexadecylammonium chloride using the
process mentioned in Park et al. (Park, J. H., Jana, S. C, Macromolecules, 2003, 36, pp. 2758-2768). The
modified nanoclay shall be herein designated as OMMT.
Natural Montmorillonite clay modified with a quaternary ammonium salt, Cloisite.RTM.30B (C30B) having
a cation exchange capacity of 90.0 meq/100 grams of clay was procured from Southern Clay Products.
Among the three clays discussed above, only C30B is reactive to the isocyanate end groups of the
polymer chains in TPU matrix used in the present invention to form a polymer nanocomposite. The
methyl, tallow, bis-2-hydroxyethyl, quaternary ammonium ions in C30B have a structure as shown below:
where T (tallow) is an alkyl group with approximately 65% Csub.18H.sub.37, 30% Csub.16H.sub.33, 5%
Csub.14H.sub.29, and the anion that is "bound" to the cation is a chloride anion. The -
CH.sub.2CH.sub.20H groups in Clay 2 are capable of reacting with the --NCO groups on the
polyurethane polymer chains. Accordingly, C30B can be described as a "reactive organically modified
clay," or a "reactive organic clay" or "organoclay" (US patent No. 20070072991).
EXAMPLE-2
POM/TPU blends as well as the nanocomposite blends were produced at a L/D ratio of at least 40 using
a twin-screw extruder (Haake, Germany). The polymers and layered silicates intercalated with organic
substances were added in the first zone using polymer or powder scales. The batch was compounded at
temperatures from 190 to 210degree. C. and a speed of 80 min.sup.-1 for 6 minutes. The compounded
nanocomposite blends were made into test specimens using 80T injection moulding machine
(ES330/80HL, ENGEL Austria) as per ASTMD having clamping force 800 kN fitted with a dehumidifier
(Bryair, Germany) at a temperature range of 195- 210° C.
EXAMPLE-3
The spacing between the silicate sheets was determined by WAXD analysis (WAXD=wide angle X-ray
diffraction) using Phillips 'X'Pert MPD, Japan fitted with a diffractometer andrecording accessories
employing nitrogen filtered Co Kα radiation (λ=0.179 nm) operated at 40 KV. Based on this and on TEM
(Transmission Electron Microscopy) recordings, made from a Philips 430t microscope operating at 300


kV, using thin sections 120 nm prepared by cryo-microtome (Reichert Jung ultra-microtome) at a
temperature of 90.degree.C. and the specimens were kept in OsO4 vapour for 90 mins. Subsequently
conclusions were drawn regarding the degree of exfoliation/intercalation or dispersion of the nanoclays
within the blend matrix.
EXAMPLE-4
The mechanical properties of the blends and the nanocomposite blends were examined after conditioning
of the specimens at 24 Degree. C and 55% RH. States, using a notch-izod impact strength test (Ceast
S.p.A, Italy, Model-P/N 6963) according to ASTMD 256,tensile test according to ASTMD 638 and flexural
test as per ASTMD 790 (UTM LR-100K, Lloyd Instrument, UK). Five to seven moulded samples for each
formulation were measured to determine the variability at 23. Degree C and 55% RH.
REFERENCE EXAMPLE
Polyoxymethylene material (POM) with density of 1.42 g per ccm and Melt Flow Index of 7g per 10min
obtained from DuPont chemicals USA, was compounded with Thermoplastics elastomer (TPU),
Desmopan 385 L with density of 1.2 g per ccm, Melt Flow Index of 1g per 10min, obtained from Bayer
material science, Germany, at different ratios of POM: TPU, 100: 0, 90:10, 80:20, 70:30. 65:35,60:40.
and 50:50.
The results are shown in the tables below.

REFERENCE EXAMPLE
Polyoxymethylene material (POM) with density of 1.42 g per ccm and Melt Flow Index of 7g per 10min
was compounded with Thermoplastics elastomer (TPU), Desmopan 385 L with density of 1.2 g per ccm,

Melt Flow Index of 1g per 10min, and at different ratios of POM: TPU, 100: 0, nanosized fillers of POM:
TPU: nanosized fillers at 64: 35: 1, 62: 35: 3, 60: 35: 5.

EXAMPLE 5
A particular benefit anticipated from these nanocomposites is the generation of a blend system with
significantly improved impact strength of POM while retaining the tensile strength its modulus and flexural
strength its modulus. When a stress or deformation is applied to the nancomposite, the exfoliated clay
layers would be anticipated to increase modulus and tensile strength.

EXAMPLE 6
Referring to Table I, it is evident that with the increase in TPU content, there is a decrease in tensile
strength and modulus as well as flexural strength and modulus of virgin POM with a substantial increase
in the impact properties. The blend prepared at 35% TPU concentration exhibited optimum performance
with an increase of 135 % in impact strength as compared with virgin POM. This behaviour is attributed to
small particle size of TPU, which results in improved compatibility at this concentration. However, beyond
35 wt% of TPU, the impact strength decreases which may be due to the coalescence of TPU particles
with the matrix polymer. This phenomenal transition is also due to the presence of elastomeric phase,
which gets deformed during impact test thereby absorbing part of impact energy. However, nearly 42.87
% and 80% decrease in tensile strength and modulus and 50.01 % and 138.13% in flexural strength and
modulus was observed with the incorporation of 35% TPU which is primarily due to the presence of soft
elastomeric phase which reduces the crystallinity and stress level of virgin matrix to produce shear
yielding. All the blends exhibit higher elongation as compared with the virgin matrix with POM:TPU blend
to about 44.58 % at 35% TPU loading.
Mechanism of POM toughening can be thus interpreted to occur through microlayer plasticization - the
elastomer becomes dispersed in the form of microlayers within the POM matrix. In addition, high degree
of crystallinity, apart from miscibility, is a factor that causes difficulties in homogenization of polymeric
components in TPU rich blend at the molecular level and rejection of TPU dispersed particles from the
POM crystalline phase into amorphous region followed by a random agglomeration of TPU domains. This
fact is substantiated in SEM Micrographs in Fig. 1a and b wherein the elastomeric domains are
distributed within the POM matrix as micro layers at 30% TPU loading & which subsequently displays
agglomeration at higher loading of TPU.
EXAMPLE 7
Referring Table 2, the mechanical properties of the blend nanocomposites (at 65:35 optimized blend
ratio) are very encouraging and surprising. The impact strength increases to the tune of 215% as
compared with the virgin matrix and to about.34%as compared to the optimized blend with just 5%
loading of C30B. Incorporation of OMMT also increases the strength modestly to 180.40 J/m at 5 wt%
loading. Tensile strength of the blend also increased with addition of nanoclay, and was almost
comparable to the POM matrix. At this level the tensile strength of the blend was improved by a factor of
53% to a value of 52.36 MPa. Tensile Modulus of POM/TPU blend also reached to a same value, from
907.42 to 1109 MPa, a much more modest reduction than expected with the incorporation of only TPU in
the POM matrix. Tensile strength and modulus increased to 65% and 32.36 % as compared with
POM/TPU blend wth the addition of 5 wt5 of C30B. Even similar behaviour was also noticed incase of the


flexural properties. Flexural strength and modulus of the blend matrix increased to the tune of 66.16 %
and 48.53% & 41% and 36.1% with the incorporation of C30B and OMMT respectively. The mechanical
findings are also corroborated with morphological interpretations.
REFERENCE EXAMPLE
The nanocomposites prepared using methyl, tallow, bis-2-hydroxyethyl, quaternary ammonium
intercalants i.e organically reactive modifier exhibited better dispersion of the clay layers within the
polymer matrix than the hexadecylammonium intercalated (OMMT) and Na-MMT (as confirmed by
increased d-spacing from WAXD). This well dispersed exfoliated/intercalated nanomorphology is
attributed to the modification of clay with quaternary ammonium salt which lowers electrostatic interaction
between the clay layers, enlarged their intergallery spacing thus facilitating efficient dispersion of the clay.
Furthermore, it may be also due to reaction of the -NCO end groups of the TPU matrix with the -
CH2CH20H groups in C30B that has resulted in improved compatibility with the blend matrix.
EXAMPLE 8
X-ray Diffraction:
Referring Fig. 2 the wide-angle X-Ray diffraction patterns of nanoclays; Na-MMT, C30B, OMMT
respectively. The d001 spacing was calculated from peak positions using Braggs law 2dsin0 = nλ where λ
is the wavelength of X-ray radiation used in the diffraction experiment, the d spacing between diffraction
lattice planes and θ is the measured half diffraction angle or glancing angle. It is evident that Na-MMT
(Fig. 2 (a)) shows a diffraction peak at 2θ = 7.98° corresponding to a d-spacing of 12.8 A0. The XRD
pattern of treated clay OMMT (Figure 2(b)) reveals a reflection peak at 26 =6.73° with a d spacing of 13.3
A0. This resultant increase in the basal spacing confirms intercalation in Na-MMT clay on modification
with hexadecylammonium. Similarly, the x-ray diffractogram of treated clay C30B (Figure 2(c)) shows a
diffraction peak around 5.61° corresponding to a d-spacing of 18.25 A0, thus indicating intercalation in the
nanoclay in presence of methyl, tallow, bis-2-hydroxyethyl, quaternary ammonium as surfactant.
REFERENCE EXAMPLE
Referring Fig. 3(a), the WAXD patterns of POM/TPU blend nanocomposite prepared using organically
reactive clay i.e exhibits absence of basal deflections in the x-ray diffractograms. This indicates exfoliation
of the clay galleries in the nanocomposite blend in presence C30B nanoclay with methyl tallow bis-2-
hydroxy ethyl quaternary ammonium salt as surfactant. In case of blend nanocomposite with 5% OMMT a
diffraction of peak at 2θ=2.95° which corresponds to d001=34.7A was observed thus revealing intercalation
of the clay galleries within the blend matrix (Fig. 3(b)). However, at 5% Na-MMT loading, the WAXD
patterns exhibited a d001 spacing around 5.8 A indicating intercalated structure of the clay within the blend
matrix (Fig. (3c)). However, formation of agglomerates and incompatibility of Na-MMT with the blend
matrix have been observed from TEM micrograph which is discussed in the later section. The WAXD
patterns were also corroborated with TEM Micrographs.


Example 9
Referring Fig. 4(a) the TEM microgrpahs of C30B blend nanocomposite reveals partial exfoliation of
montmorillonite. Therefore, mixed structure is proposed for obtained blend nanocomposites containing
both exfoliated regions and intercalated microscale stacks of MMT. One can consider peeling of external
layers from the grain of montmorillonite filler as a mechanism ruling the MMT exfoliation in polymer matrix
during melt mixing, whereby the grain size could play a crucial role in MMT dispersing. This considerable
changes in the morphology of injection molded samples of the blend nanocomposites, as compared to
virgin blend matrix has resulted an unexpected synergic effect - both tensile and flexural strength and its
modulus as well as ductility were improved. Fig. 4(b) depicts intercalated layers as well as unintercalated
factoids within the blend matrix with the incorporation of 5% OMMT. Some exfoliated layers of OMMt was
also observed. However, addition of Na-MMT resulted in agglomeration within the matrix polymer Fig.
4(c). The dispersion of the clay particles was poor and many large aggregates (in microns) were
observed. There are some finely exfoliated clay layers and some unexfoliated individual clay particles.
This confirms less compatibility between the hydrophobic matrix polymer and Na-MMT.
EXAMPLE 10
The nanocomposites blends are useful as molding resins which can be used as light weight engineering
molded components wherein improved mechanical performance is desired.
While in accordance with the patent statutes the best mode and preferred embodiment has been set
forth, the scope of the invention is not limited thereto, but rather by the scope of the attached claims.


We claim:
2. A nanocomposite blend as claimed in claim 1, wherein the said nanofiller is selected from one or
more of montmorillonite, sodium montmorillonite, calcium montmorillonite, magnesium
montmorillonite, bentonite, kaolinite, mica, laponite, hectorite, saponite, vermiculite, sauconite,
kenyalite or magadite.
1. A nanocomposite blend, comprising (a) organically modified nanofiller, and at least one (b)
thermoplastic polyoxymethylene(POM), (c) thermoplastic elastomer; thermoplastic Polyurethane
(TPU).
2. A nanocomposite blend as claimed in claim 1, wherein the said nanofiller is selected from one or
more of montmorillonite, sodium montmorillonite, calcium montmorillonite, magnesium
montmorillonite, bentonite, kaolinite, mica, laponite, hectorite, saponite, vermiculite, sauconite,
kenyalite or magadite.
3. A nanocomposite blend as claimed in claim 2, wherein said the nanofiller is organically modified
with ammonium, quaternary alkylammonium, alkyl amine derivatives of aliphatic, aromatic or
arylaliphatic amines, phosphines or sulfonium derivatives of aliphatic, or aromatic amines.
4. A nanocomposite blend as claimed in claims 2 or 3 wherein the clay layers of the organically
modified nanofiller are largely intercalated that influences the surface tension of the nanofiller so
that polarity and the overall surface energy value drops
5. The nanocomposite blend as claimed in claim 4, wherein the said organically modified nanofiller
is present in the said nanocomposite blend from 1-7 wt % of the said nanocomposite.
8. The nanocomposite blend of claim 1, wherein the said nanocomposite blend comprises of
Thermoplastic elastomer, Thermoplastic Polyurethane, (TPU) to the tune of 30 to 40 wt% of total
100 wt% of POM matrix.
7. The nanocomposite blend as claimed in claim 6, wherein the POM: TPU: Nanofiller composition
of 60:35:5 has substantially high impact strength of at least 215% and 34% higher than POM
matrix and the POM/TPU blend
8. The nanocomposite blend as claimed in claim 6, wherein the wherein the POM: TPU: Nanofiller
composition of 60:35:5 has substantially high tensile strength and modulus of at least 65% and
32.36 % higher than the POM/TPU blend.
9. The nanocomposite blend as claimed in claim 6, wherein the POM: TPU: Nanofiller composition
of 60:35:5 has substantially high flexural strength and modulus of at least 66.16 % and 48.53%
higher than the POM/TPU blend.
10. The nanocomposite blend as claimed in claim 6, wherein the clay galleries of the nanofiller
undergoes exfoliation within the blend matrix when organically modified with methyl, tallow, bis-2-
hydroxyethyl, quaternary ammonium as surfactant

The present invention relates to melt mixing of Polyoxymethylene(POM)/Thermoplastic Polyurethane
(TPU) blends and intercalated nanofiller organically modified with various quaternary alkyl ammonium
surfactants to form nanocomposite blend. These nanocomposite blend are found to exhibit significantly
improved impact strength while retaining the tensile strength and modulus and flexural strength and
modulus of POM. Impact strength increases to the tune of 215% as compared with the virgin POM matrix
and to about 34% as compared to the optimized POM/TPU blend matrix of ratio 65:35 with just 5%
loading of C30B nanoclay, organically modified with methyl, tallow, bis-2-hydroxy ethyl quaternary
ammonium intercalant. A similar increase in tensile strength and modulus and flexural strength and
modulus of the nanocomposite blend to the tune of 65% and 32.36% and 66.16% and 48.53% was
observed. Incorporation of hexadecylammonium modified Na-MMT (OMMT) also increased the impact
strength of POM/TPU blend matrix modestly to 180.40 J/m at 5 wt% loading. Tensile strength of the blend
also increased with the addition of this nanoclay by a factor of 53%, and was almost comparable to the
POM matrix. Tensile Modulus of POM/TPU blend also reached to a same value, form 907.42 to 1109
MPa, a much more modest reduction than expected with the incorporation of only TPU in the POM matrix.
Flexural strength and modulus of the blend matrix increased to the tune of 41% and 36.1% respectively.
WAXD patterns of the blend nanocomposites displayed exfoliated nanomorphology in C30B blend
nanocomposites with intercalated structure in the OMMT blend nanocomposite system. TEM micrographs
also confirmed improved exfoliation as well as intercalation in C30B blend nanocomposite system.

Documents:

00862-kol-2007-abstract.pdf

00862-kol-2007-claims.pdf

00862-kol-2007-correspondence others 1.1.pdf

00862-kol-2007-correspondence others.pdf

00862-kol-2007-description complete.pdf

00862-kol-2007-drawings.pdf

00862-kol-2007-form 1.pdf

00862-kol-2007-form 18.pdf

00862-kol-2007-form 2.pdf

00862-kol-2007-form 3.pdf

00862-kol-2007-form 5.pdf

00862-kol-2007-form 9.pdf

862-kol-2007-correspondence.pdf

862-KOL-2007-DESCRIPTION (COMPLETE)-1.1.pdf

862-KOL-2007-DRAWINGS-1.1.pdf

862-kol-2007-examination report.pdf

862-KOL-2007-FORM 1-1.1.pdf

862-kol-2007-form 18.pdf

862-KOL-2007-FORM 2-1.1.pdf

862-KOL-2007-FORM 3-1.1.pdf

862-kol-2007-form 3.pdf

862-KOL-2007-FORM 5-1.1.pdf

862-kol-2007-form 5.pdf

862-kol-2007-form 9.pdf

862-kol-2007-granted-abstract.pdf

862-kol-2007-granted-claims.pdf

862-kol-2007-granted-description (complete).pdf

862-kol-2007-granted-drawings.pdf

862-kol-2007-granted-form 1.pdf

862-kol-2007-granted-form 2.pdf

862-kol-2007-granted-specification.pdf

862-KOL-2007-OTHER DOCUMENT.pdf


Patent Number 248569
Indian Patent Application Number 862/KOL/2007
PG Journal Number 30/2011
Publication Date 29-Jul-2011
Grant Date 26-Jul-2011
Date of Filing 08-Jun-2007
Name of Patentee DR. SANJAY KUMAR NAYAK
Applicant Address CIPET, B/25, CNI COMPLEX, PATIA, BHUBANESWAR
Inventors:
# Inventor's Name Inventor's Address
1 DR. SANJAY KUMAR NAYAK CIPET, B/25, CNI COMPLEX, PATIA, BHUBANESWAR -751 024
2 DR. SMITA MOHANTY CIPET, B/25, CNI COMPLEX, PATIA, BHUBANESWAR - 751 024
PCT International Classification Number C08G2/28
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA