Showing papers on "Vinyl acetate published in 2003"
TL;DR: A series of polymer-clay nanocomposite (PCN) materials that consist of poly(vinyl alcohol) (PVA) and layered montmorillonite (MMT) clay are prepared by effectively dispersing the inorganic nanolayers of MMT clay in organic PVA matrix via an in situ free radical polymerization with AIBN as initiator as discussed by the authors.
297 citations
TL;DR: In this paper, eight xanthates were synthesized to induce living free radical polymerization of vinyl acetate, yielding low polydispersity (PDI < 1.2) poly(vinyl acetate) of molecular weights exceeding 5 x 10(4) g.
Abstract: Eight xanthates were synthesized to induce living free radical polymerization of vinyl acetate. Four compounds, methyl (4-methoxyphenoxy)carbonothioylsulfanyl acetate, methyl (methoxycarbonothioyl)sulfanyl acetate, methyl (ethoxycarbonothioyl)sulfanyl acetate and methyl (isopropoxycarbonothioyl)sulfanyl acetate were identified as suitable MADIX/RAFT agents, yielding low polydispersity (PDI < 1.2)poly(vinyl acetate) of molecular weights exceeding 5 x 10(4) g.mol(-1). All suitable MADIX/RAFT agents exhibited extended periods of inhibition (0.3 h < t(inh) < 10 h) and moderate rate retardation. The ability of these compounds to control vinyl acetate polymerization can be correlated with the electron density on the central carbon atom of the xanthate. Electrospray ionizaiton mass spectrometric analysis was performed to complete the investigation on the new MADIX/RAFT agents.
289 citations
TL;DR: In this paper, Colloids of TiO2, where rutile was the only crystal modification which could be detected, with ca. 2.5 nm average particle diameter were synthesized by hydrolysis of TiCl4 in acidic solutions.
Abstract: Colloids of TiO2, where rutile was the only crystal modification which could be detected, with ca. 2.5 nm average particle diameter were synthesized by hydrolysis of TiCl4 in acidic solutions. The as-prepared particles were incorporated in polymers such as poly(vinyl alcohol) (PVAL), partially hydrolyzed poly(vinyl acetate) (PVAC88), polyvinylpyrrolidone, and poly(4-vinylpyridine). Nanocomposites transparent in the visible range were obtained. The highest TiO2 contents in such materials were achieved with PVAL and PVAC88, with TiO2 contents of ca. 35 wt.-% (i.e. 10.5 vol.-%). In particular, the nanocomposites with TiO2 contents above 24 wt.-% acted as efficient UV filters for radiation up to ca. 360 nm. At very low TiO2 contents, an absorption maximum of the embedded TiO2 particles was observed at 225 nm with an extinction coefficient of 140 000 cm−1 and a full width at half maximum of 45 nm, i.e. not only the absorption at the maximum at 225 nm but also at the flank of this band contributed significantly to the broadband UV absorption in the nanocomposites at higher TiO2 fractions. The incorporation of TiO2 enhanced the refractive index of the nanocomposites: for instance a refractive index of 1.609 was measured for a nanocomposite comprising 10.5 vol.-% TiO2 in PVAL, compared with 1.521 for the pristine polymer.
TEM image of a section of a nanocomposite of poly(vinyl alcohol) and 11 wt.-% TiO2 (appearing dark).
278 citations
01 Jan 2003
TL;DR: In this article, eight xanthates were synthesized to induce living free radical polymerization of vinyl acetate, yielding low polydispersity (PDI < 1.2) poly(vinyl acetate) of molecular weights exceeding 5 x 104 g·mol-1.
Abstract: Eight xanthates were synthesized to induce living free radical polymerization of vinyl acetate. Four compounds, methyl (4-methoxyphenoxy)carbonothioylsulfanyl acetate, methyl (methoxycarbonothioyl)sulfanyl acetate, methyl (ethoxycarbonothioyl)sulfanyl acetate and methyl (isopropoxycarbonothioyl)sulfanyl acetate were identified as suitable MADIX/RAFT agents, yielding low polydispersity (PDI < 1.2) poly(vinyl acetate) of molecular weights exceeding 5 x 104 g·mol-1. All suitable MADIX/RAFT agents exhibited extended periods of inhibition (0.3 h < tinh < 10 h) andmoderate rate retardation. The abitity of these compounds to control vinyl acetate polymerization can be correlated with the electron density on the central carbon atom of the xanthate. Electrospray ionization mass spectrometric analysis was performed to complete the investigation on the new MADIX/RAFT agents.
232 citations
TL;DR: In this article, a degenerative transfer process using alkyl iodides as transfer agents was used to synthesize poly(vinyl acetate) with predetermined molecular weight and relatively low polydispersity.
Abstract: Controlled/living radical polymerization of vinyl acetate was achieved by a degenerative transfer process using alkyl iodides as transfer agents. Poly(vinyl acetate) with predetermined molecular weight and relatively low polydispersity was successfully synthesized. Methyl 2-iodopropionate and ethyl iodoacetate were employed as transfer agents, whereas 2,2‘-azobis(isobutyronitrile) and α-cumyl peroxyneodecanoate were used as initiators. Methyl 2-iodopropionate and ethyl iodoacetate are both efficient transfer agents, yielding polymers with good agreement between theoretical and observed molecular weights up to Mn = 20 000 and low polydispersities (Mw/Mn < 1.5). In contrast, ethyl iodide was inefficient as a transfer agent, although it retarded polymerization. The influence of temperature and the concentrations of transfer agent and initiator were studied. The structure of poly(vinyl acetate) end groups was investigated using 1H NMR. The iodo-terminated chain ends were unstable and decomposed to aldehyde mo...
184 citations
TL;DR: In this article, a transesterification of n-octanol with vinyl acetate was studied at 30°C as a model reaction by employing different lipases as catalysts such as Psedomonas species lipase immobilized on diatomite, free Candida rugosa lipase.
179 citations
177 citations
TL;DR: In this paper, a wide variety of rheological observations, such as Payne effect, percolation threshold and elastic effects, of non-porous silica dispersed in a ethylene vinyl acetate copolymer (EVA, 60% of Vinyl acetate) were studied in the molten state or diluted solutions in xylene.
177 citations
Patent•
07 Jan 2003TL;DR: In this paper, a cost-saving scheme to bypass the methyl acetate processing at production or plant facilities and utilize the methylacetate in an integrated methanol carbonylation unit is discussed.
Abstract: The present invention is directed to using methyl acetate from a vinyl acetate -based or a vinyl-or ethylene-alcohol based polymer or copolymer process directly for use in a methanol carbonylation production process to produce acetic acid, acetic anhydride, or a coproduction of each. Methyl acetate is a by-product of commercial polyvinyl-alcohol or alkene vinyl alcohol copolymer-based processes. Generally, this material is processed to recover methanol and acetic acid. Discussed herein is a cost-saving scheme to by-pass the methyl acetate processing at production or plant facilities and utilize the methyl acetate in an integrated methanol carbonylation unit. The scheme discussed eliminates an expensive hydrolysis step often associated with the polymer process.
173 citations
TL;DR: In this article, it was shown that the cloud point pressures needed to dissolve ∼5 ¼ w% poly(methyl acrylate) (PMA) at 298 K are significantly greater than those required to dissolve PVAc, even though a PMA repeat group has the same number of carbon, hydrogen, and oxygen atoms as in PVA c. This large difference in dissolution pressures is attributed to the lack of accessibility of the carbon dioxide to the carbonyl group in PMA.
167 citations
Patent•
19 Mar 2003TL;DR: In this paper, a water-soluble copolymer film was proposed for making pouches to contain a unit dose of liquid detergent, such as a liquid laundry detergent.
Abstract: Generally speaking, the present invention is a water-soluble copolymer film comprising a hydrolyzed copolymer of vinyl acetate and a second monomer, the resultant polyvinyl alcohol copolymer having a degree of hydrolysis, expressed as a percentage of vinyl acetate units converted to vinyl alcohol units, of from about 90% to 100%. The second monomer is preferably selected from the group of monomers having carboxylate functionality or sulfonate functionality. The resulting water-soluble copolymer film is disclosed for use in making pouches to contain a unit dose of liquid detergent, such as a liquid laundry detergent. However, it is an aspect of the copolymer film that film solubility is not significantly affected adversely by the detergent. Such film produces pouches having a greater storage shelf-life over prior art water-soluble film.
TL;DR: In this paper, a copolymerization of vinyl acetate and divinyl benzene using oleic acid-stabilized magnetic colloids as magnetic cores was described by the Langevin function.
TL;DR: In this article, 1-Butyl-2,3-dimethylimidazolium tetrafluoroborate ([bdmim]BF 4 ) was found to be an excellent solvent to realize a lipase-recycling system using vinyl acetate as acyl donor.
Abstract: 1-Butyl-2,3-dimethylimidazolium tetrafluoroborate ([bdmim]BF 4 ) was found to be an excellent solvent to realize a lipase-recycling system using vinyl acetate as acyl donor. No accumulation of an acetaldehyde oligomer was observed in this solvent system and it was possible to use the lipase repeatedly 10 times while still maintaining perfect enantioselectivity and high reactivity.
TL;DR: Using an (R,S)-BINAPHOS-Rh(I) catalyst that is covalently anchored to a highly cross-linked polystyrene support, asymmetric hydroformylation of olefins was performed in the absence of organic solvents to realize the conversion of an olefin library into an optically active aldehyde library.
Abstract: Using an (R,S)-BINAPHOS-Rh(I) catalyst that is covalently anchored to a highly cross-linked polystyrene support, asymmetric hydroformylation of olefins was performed in the absence of organic solvents. The reaction of cis-2-butene, a gaseous substrate, provided (S)-2-methylbutanal with 100% regioselectivity and 82% ee upon treatment with H(2) (12 atm) and CO (12 atm) in a batchwise reactor equipped with a fixed bed. The polymer-supported catalyst was applicable to a continuous vapor-flow column reactor, and thus, 3,3,3-trifluoropropene was converted into (S)-2-trifluoromethylpropanal with an iso/normal ratio of 95/5 and 90% ee. Less volatile olefins, such as styrene, vinyl acetate, 1-alkenes, and fluorinated alkenes, were successfully converted into the corresponding isoaldehydes with high ee values, when they were injected through a supercritical CO(2)-flow column reactor. Successive injection of a series of olefins realized the conversion of an olefin library into an optically active aldehyde library.
TL;DR: In this article, a nuclear magnetic resonance spectroscopy (NMR) analysis of poly( l -lactic acid) (PLA) and polyvinyl acetate-co-vinyl alcohol (PVAc) copolymers was performed.
TL;DR: In this article, an asymmetric tubular alumina-supported poly(vinyl acetate) (PVAc) and poly (vinyl pyrrolidone)(PVP) membranes were created and characterized by pervaporation separation of binary mixtures of methanol and methyl tert-butyl ether (MTBE).
TL;DR: The rubber nanocomposites containing ethylene vinyl acetate (EVA) and organomodified layered double hydroxide (LDH) as nanofiller have been prepared by solution intercalation method and characterized.
Abstract: The rubber nanocomposites containing ethylene vinyl acetate (EVA) having 60 wt % of vinyl acetate content and organomodified layered double hydroxide (DS-LDH) as nanofiller have been prepared by solution intercalation method and characterized. The XRD and TEM analysis demonstrate the formation of completely exfoliated EVA/DS-LDH nanocomposites for 1 wt % filler loading followed by partially exfoliated structure for 5–8 wt % of DS-LDH content. EVA/DS-LDH nanocomposites show improved mechanical properties such as tensile strength (TS) and elongation at break (EB) in comparison with neat EVA. The maximum value of TS (5.1 MPa) is noted for 3 wt % of DS-LDH content with respect to TS value of pure EVA (2.6 MPa). The data from thermogravimetric analysis show the improvement in thermal stability of the nanocomposites by ≈15°C with respect to neat EVA. Limiting oxygen index measurements show that the nanocomposites act as good flame retardant materials. Swelling property analysis shows improved solvent resistance behavior of the nanocomposites (1, 3, and 5 wt % DS-LDH content) compared with neat EVA-60. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Patent•
14 Mar 2003
TL;DR: In this article, the authors proposed a method for composite compositions that, over a wide range of single-wall carbon nanotube loading, have electrical conductivities exceeding those known in the art by more than one order of magnitude.
Abstract: The invention relates to a composite comprising a weight fraction of single-wall carbon nanotubes and at least one polar polymer wherein the composite has an electrical and/or thermal conductivity enhanced over that of the polymer alone. The invention also comprises a method for making this polymer composition. The present application provides composite compositions that, over a wide range of single-wall carbon nanotube loading, have electrical conductivities exceeding those known in the art by more than one order of magnitude. The electrical conductivity enhancement depends on the weight fraction (F) of the single-wall carbon nanotubes in the composite. The electrical conductivity of the composite of this invention is at least 5 Siemens per centimeter (S/cm) at (F) of 0.5 (i.e. where single-wall carbon nanotube loading weight represents half of the total composite weight), at least 1 S/cm at a F of 0.1, at least 1×10 −4 S/cm at (F) of 0.004, at least 6×10 −9 S/cm at (F) of 0.001 and at least 3×10 −16 S/cm (F) plus the intrinsic conductivity of the polymer matrix material at of 0.0001. The thermal conductivity enhancement is in excess of 1 Watt/m-° K. The polar polymer can be polycarbonate, poly(acrylic acid), poly(acrylic acid), poly(methacrylic acid), polyoxide, polysulfide, polysulfone, polyamides, polyester, polyurethane, polyimide, poly(vinyl acetate), poly(vinyl alcohol), poly(vinyl chloride), poly(vinyl pyridine), poly(vinyl pyrrolidone), copolymers thereof and combinations thereof. The composite can further comprise a nonpolar polymer, such as, a polyolefin polymer, polyethylene, polypropylene, polybutene, polyisobutene, polyisoprene, polystyrene, copolymers thereof and combinations thereof.
TL;DR: In this article, the authors show how the kind of crosslinking agents and their contents influence important properties of acrylic based pressure-sensitive adhesive (PSA) dispersions such as tack, adhesion and cohesion.
Abstract: This publication shows how the kind of crosslinking agents and their contents influence important properties of acrylic based pressure-sensitive adhesive (PSA) dispersions such as tack, adhesion and cohesion. Synthesized PSAs based on acrylic polymers, containing 2-ethylhexyl acrylate, butyl acrylate, vinyl acetate, styrene and acrylic acid are used in the preparation of self-adhesive dispersions used as coating of polyethylene foams and poly(vinyl chloride) and polyester foils.
© 2003 Society of Chemical Industry
Patent•
10 Oct 2003TL;DR: Blends of amorphous and semicrystalline polymers having shape memory properties were prepared by blending a crystalline polymer such as poly(vinylidene fluoride), polylactide, poly(hydroxxybutyrate), poly(ethylene glycol) polyethylene, polymethylene-co-vinyl acetate, poly (vinyl chloride), polyvinyl idene chloride, and copolymers of poly(polyvinylidsene chloride) and poly(pinyle chloride) as discussed by the authors.
Abstract: Blends of amorphous and semicrystalline polymers having shape memory properties were prepared by blending a crystalline polymer such as poly(vinylidene fluoride), polylactide, poly(hydroxxybutyrate), poly(ethylene glycol) polyethylene, polyethylene-co-vinyl acetate, poly(vinyl chloride), poly(vinylidene chloride) and copolymers of poly(vinylidene chloride) and poly(vinyle chloride) and an amorphous polymer such as poly(vinyl acetate), poly methyl acrylate, poly ethyl acrylate, atactic poly methyl methacrylate, isotactic poly methyl methacrylate, syndiotactic poly methyl methacrylate and other poly alkyl methacrylates. The method for preparing the polymeric materials and applications thereof, for example, as smart medical devices, are also disclosed.
TL;DR: An efficient lipase-catalyzed conversion of sophorolipid ethyl ester to 6'-monoacylated derivatives and regioselective monoacylation of an amide derivative at the 6'- and 6' '-positions using Novozym 435 and Lipase PS-C are described.
Abstract: Novel enzyme-mediated synthetic routes were developed to provide a new family of sophorolipid derivatives and glycolopid-based amphiphilic monomers. These compounds are of great interest for their potential use in immunoregulation, as well as for other biological properties. In the present work, an efficient lipase-catalyzed conversion of sophorolipid ethyl ester to (a) the 6'-monoacylated derivatives using Novozym 435, (b) 6' '-monoacylated derivatives using Lipase PS-C, (c) secondary amide derivatives using Novozym 435, and (d) 6',6' '-diacylated amide derivatives using Novozym 435 in an one-pot reaction and (e) the regioselective monoacylation of an amide derivative at the 6'- and 6' '-positions using Novozym 435 and Lipase PS-C, respectively, are described. The ethyl ester produced by esterification of the sophorolipid mixture with sodium ethoxide was subjected to acylation catalyzed by Novozym 435 in dry tetrahedrofuran (THF) with vinyl acetate and vinyl methacrylate to produce 6'-monoacylated derivatives. In contrast, Lipase PS-C catalyzed acylations of sophorolipid ethyl ester in dry THF with vinyl acetate and vinyl methacrylate to give the corresponding 6'-monoacylated derivatives. Novozym 435 mediated amidation of sophorolipid ethyl ester in dry THF with phenethylamine, tyramine, p-methoxyphenethylamine, 2-(p-tolyl)ethylamine, and p-fluorophenethylamine generated the corresponding secondary amides but not tertiary amides. The formation of diacyl derivatives of amides was achieved by their treatment with vinyl acetate and vinyl methacrylate in dry THF using Novozym 435 as catalyst. The conversion of sophorolipid ethyl ester to the same diacyl derivatives of amide (i.e., both amidation and acylation) in high yield was also demonstrated in dry THF by a one-pot reaction using Novozym 435. Furthermore, regioselective monoacylation of a sophorolipid amide at 6' and 6' ' in dry THF with vinyl acetate and vinyl methacrylate using Novozym 435 and Lipase PS-C was also demonstrated.
TL;DR: The role of metal oxides on the thermal decomposition of poly(vinyl chloride) (PVC) and their blends was investigated by thermogravimetry (TGA) as discussed by the authors.
Abstract: The role of metal oxides on the thermal decomposition of poly(vinyl chloride) (PVC) and poly(vinyl acetate) (PVAC) and their blends was investigated by thermogravimetry (TGA). While the degradation of PVAC was mildly affected by the presence of metal oxides, the degradation of PVC was greatly influenced by metal oxides. Both polymers followed a two-step degradation mechanism involving chlorine or acetate radical removal followed by polyolefinic backbone breakage. The isokinetic temperatures and rate determined from the compensation plots indicated that the mode of olefinic backbone breakage is the same for both the polymers. FTIR studies after the first stage showed the disappearance of the C-Cl of PVC and C=O and C-O groups of PVAC, suggesting the formation of a polyolefinic chain. Blends of PVC-PVAC were obtained by solution blending by dissolving the polymers in tetrahydrofuran. Scanning electron microscopy and TGA showed complete miscibility of polymers in the blend. The first-stage degradation of the blend was greatly influenced by the presence of PVC and metal oxides, suggesting that hydrogen chloride liberated from PVC influenced the decomposition behavior of PVAC. The second-stage degradation (olefinic breakage) of the blends was mildly affected by the metal oxides and the breakage was similar to that of pure polymers.
TL;DR: In this article, carboxylic acids with terminal alkynes in the presence of catalytic amounts of [Ir(cod)Cl]2 and Na2CO3 gave the corresponding 1-alkenyl esters.
TL;DR: In this article, 2,4-Dichlorophenyl methacrylate and vinyl acetate copolymerized with different feed ratios using dimethyl formamide (DMF) as a solvent and 2,2′-azobisisobutyronitrile (AIBN) as an initiator at 70°C.
Abstract: 2,4-Dichlorophenyl methacrylate (2,4-DMA) and vinyl acetate (VAc) were copolymerized with different feed ratios using dimethyl formamide (DMF) as a solvent and 2,2′-azobisisobutyronitrile (AIBN) as an initiator at 70°C. The copolymers were characterized by infrared (IR) spectroscopy. Copolymer compositions were determined by ultraviolet (UV) spectroscopy. The monomer reactivity ratios were evaluated by the Fineman–Ross method. Average molecular weight and polydispersity index were determined by gel permeation chromatography (GPC), and the intrinsic viscosities of polymers were also discussed. Thermogravimetric analyses of polymers were carried out under a nitrogen atmosphere. The homo- and copolymers were tested for their antimicrobial activity against selected microorganisms. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 895–900, 2003
TL;DR: Based on pure MCM-22 precursor, MCM36 was produced by swelling and pillaring with SiO2 pillars, and the resulting material contained a mesoporous region between the microporous layers.
Abstract: Based on pure MCM-22 precursor, MCM-36 was produced by swelling and pillaring with SiO2 pillars. These materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis/differential scanning calorimetry (TGA/DSC), MAS NMR, and N2 adsorption isotherms. Compared with the MCM-22 sample, the resulting MCM-36 material contains a mesoporous region between the microporous layers, with a mesopore volume of 0.472 cm3/g, and the surface area increased up to 671 m2/g. Lipase from Candida antarctica B (CALB) was immobilized on both supports by physical adsorption at equilibrium. Twenty milligrams of CALB/g of MCM-22 was adsorbed on the external surface of crystals, while only 4 mg CALB/g support was adsorbed onto the mesoporous hybrid material MCM-36. The mechanism of adsorption was also discussed. The acylation of alcohols (1-butanol and 1-octanol) by vinyl esters (vinyl acetate and vinyl stearate) was used as a test reaction in order to evaluate the catalytic activity of MCM-36-immobilized lipase. The test reaction indicated MCM-36-immobilized enzyme as an active catalyst for the acylation and its activity was approximately two times higher than that of the free lipase (for the vinyl acetate/1-butanol system).
TL;DR: In this article, the compatibility of low-density polyethyl ene and poly(ethylene-co-vinyl acetate) containing 18 wt % vinyl acetate units (EVA-18) was studied.
Abstract: The compatibility of low-density polyethyl- ene and poly(ethylene-co-vinyl acetate) containing 18 wt % vinyl acetate units (EVA-18) was studied. For this purpose, a series of different blends containing 25, 50, or 75 wt % EVA-18 were prepared by melt mixing with a single-screw extruder. For each composition, three different sets of blends were prepared, which corresponded to the three different temperatures used in the metering section and the die of the extruder (140, 160, and 180°C), at a screw rotation speed of 42 rpm. Blends that contained 25 wt % EVA-18 were also prepared through mixing at 140, 160, or 180°C but at a screw speed of 69 rpm. A study of the blends by differential scanning calorimetry showed that all the prepared blends were heterogeneous, except that containing 75 wt % EVA-18 and prepared at 180°C. However, because of the high inter- facial adhesion, a fine dispersion of the minor component in the polymer matrix was observed for all the studied blends with scanning electron microscopy. The tensile strengths and elongations at break of the blends lay between the corresponding values of the two polymers. The absence of any minimum in the mechanical properties was strong evi- dence that the two polymers were compatible over the whole range of composition. The thermal shrinkage of the blends at various temperatures depended mainly on the temperature and EVA-18 content. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 841- 852, 2003
Patent•
07 Apr 2003
TL;DR: A curable composition of functionalized poly(arylene ether), an alkenyl aromatic monomer, an acryloyl monomer and a polymeric additive is presented in this article.
Abstract: A curable composition includes a functionalized poly(arylene ether), an alkenyl aromatic monomer, an acryloyl monomer, and a polymeric additive effective selected from polystyrene, poly(styrene-maleic anhydride), poly(styrene-methyl methacrylate), polybutene, poly(ethylene-butylene), poly(vinyl ether), poly(vinyl acetate), and combinations thereof. The composition exhibits low shrinkage on curing and improved surface smoothness. It is useful, for example, in the manufacture of automotive body panels.
TL;DR: In this article, the dew point locus of the CO2 per-acetylated cyclodextrin binary systems shifted to higher pressures as the number of saccharides in the acetyl-ated cyclodesxtrin increased.
TL;DR: In this article, the diffusion and sorption of methyl substituted benzenes through cross-linked nitrile rubber/poly(ethylene co-vinyl acetate) (NBR/EVA) blend membranes has been studied.
TL;DR: In this article, a solution of ethylene vinyl acetate (EVA)/clay nanocomposites was synthesized by blending a solution containing 12% vinyl acetates abbreviated as EVA-12 in toluene and dispersion of dodecyl ammonium ion intercalated montmorillonite (12Me-MMT) in N,N-dimethyl acetamide (DMAc).
Abstract: Ethylene vinyl acetate (EVA)/clay nanocomposites were synthesized by blending a solution of ethylene vinyl acetate copolymer containing 12% vinyl acetate abbreviated as EVA-12 in toluene and dispersion of dodecyl ammonium ion intercalated montmorillonite (12Me-MMT) inN,N-dimethyl acetamide (DMAc). X-ray patterns of sodium montmorillonite (Na+-MMT) and 12Me-MMT exhibited d001 peak at 2θ?=7.4° and 2θ?=5.6° respectively; that is, the interlayer spacing of MMT increased by about 0.39 nm due to intercalation of dodecyl ammonium ions. The XRD trace of EVA showed no peak in the angular range of 3–10° (2θ). In the XRD patterns of EVA/clay hybrids with clay content up to 6 wt% the basal reflection peak of 12Me-MMT was absent, leading to the formation of delaminated configuration of the composites. When the 12Me-MMT content was 8 wt% in the EVA-12 matrix, the hybrid revealed a peak at about 2θ?=5.6°, owing to the aggregation of aluminosilicate layers. Transmission electron microscopic photograph exhibited that an average size of 12–15 nm clay layers were randomly and homogeneously dispersed in the polymer matrix, which led to the formation of nanocomposite with delaminated configuration. The formation of delaminated nanocomposites was manifested through the enhancement of mechanical properties and thermal stability, e.g. tensile strength of an hybrid containing only 2 wt% 12Me-MMT was enhanced by about 36% as compared with neat EVA-12.