Ethylene-vinylacetate

A series of tests [15] were conducted to compare three types of polymeric modifiers for PVC Du Ponf s Elva-loy 741, a copolymer of ethylene, vinylacetate, and carbon monoxide Goodyear s Chemigum P83, a copolymer of butadiene and acrylonitrile and 566TPU from our lab, a polyester-based TPU. Some of the results are provided in Tables 5 and 6. 

Unexpectedly, PVC/rubber blends show under certain circumstances quite a different morphology. This was shown experimentally for chlorinated polyethylene and ethylene-vinylacetate copolymers as rubber phase. 

L-ascorbic acid Potentiometric Based on ascorbate oxidase of natural source immobilised on ethylene-vinylacetate membrane Fernandes et al. (1999)... 

Figure 4.24. Vinyl acetate, ethylene and ethylene-vinylacetate copolymer formulae...

Terpolymer ethylene, propylene, diene Expandable (or Expanded) Polystyrene Environmental Stress Cracking Electrostatic Discharge Ethylene-TetraEluoroEthylene Ethylene-VinylAcetate copolymers... 

The most common type of wax crystal modifier used to reduce the pour point and filtration temperature of distillate fuel is based on ethylene vinylacetate (EVA) copolymer chemistry. These compounds are quite common throughout the fuel additive industry. The differences, however, are found in the variation in the molecular weight and the acetate ratio of the copolymer. 

Copolymers of ethylene vinylacetate are the most commonly utilized fuel wax crystal modifiers. Other compounds such as vinyl acetate-fumarate copolymers, styrene-ester copolymers, diester-alphaolefin copolymers, as well as alkyl carbamate compounds are effective wax crystal modifiers. These compounds differ in both chemical structure and in the extent of performance provided. See FIGURES 6-7 and 6-8. 

Novel styrenic-based TPEs based on blends of a thermoplastic (polystyrene or styrene acrylonitrile) with a rubber (styrene butadiene or ethylene vinylacetate), with special reference to compatibilization and dynamic vulcanization, were reported by Patel et al. The performance properties were correlated with the interaction parameter and the phase morphology of the blend components [62]. 

Membrane-reservoir systems based on solution-diffusion mechanism have been utilized in different forms for the controlled delivery of therapeutic agents. These systems including membrane devices, microcapsules, liposomes, and hollow fibres have been applied to a number of areas ranging from birth control, transdermal delivery, to cancer therapy. Various polymeric materials including silicone rubber, ethylene vinylacetate copolymers, polyurethanes, and hydrogels have been employed in the fabrication of such membrane-reservoir systems (13). 

Back-coating is the major area where bromine-based flame-retardant compounds are used for textiles. This technique is applied primarily in applications such as upholstery and wall coverings. The system would comprise an FR additive with a latex binder, the latter often based on acrylic or ethylene vinylacetate. Use of vinylidene chloride-modified acrylics reduce the amount of tire-retardant additive required. 

The pronounced amplitude dependence of the complex modulus, referred to as the Payne effect, has also been observed in low viscosity media, e.g., composites of carbon black with decane and liquid paraffin [50], carbon black suspensions in ethylene vinylacetate copolymers [51], and clay/water suspensions [52, 53]. It was found that the storage modulus decreases with... 

Even dynamic measurements have been made on mixtures of carbon black with decane and liquid paraffin [22], carbon black suspensions in ethylene vinylacetate copolymers [23], or on clay/water systems [24,25]. The corresponding results show that the storage modulus decreases with dynamic amplitude in a manner similar to that of conventional rubber (e.g., NR/carbon blacks). This demonstrates the existence and properties of physical carbon black structures in the absence of rubber. Further, these results indicate that structure effects of the filler determine the Payne-effect primarily. The elastomer seems to act merely as a dispersing medium that influences the magnitude of agglomeration and distribution of filler, but does not have visible influence on the overall characteristics of three-dimensional filler networks or filler clusters, respectively. The elastomer matrix allows the filler structure to reform after breakdown with increasing strain amplitude. 

Polyacetal resin compositions having excellent wear resistance were prepared by Kim [4], These resins consisted of polyoxymethylene polymer, ethylene vinylacetate, melamine, triethyleneglycol-bis-3-(3-t-butyl-4-hydroxy-5-methylphenyl)-propionate, and hydroxyl pentaerythritol fatty acid ester. 

Fernandes, J.C.B. Kubota, L.T. Neto, G.d.O. Potentiometric biosensor for L-ascorbic acid based on ascorbate oxidase of natural source immobilized on ethylene-vinylacetate membrane. Anal. Chim. Acta 1999, 385, 3-12. 

Adhesives may include styrene, styrene/isoprene blends, vinyl alcohol, vinyl acetate, epoxy resins, acrylates, cyanoacrylates (superglue), ethylene/vinylacetate (hot-melt), polyurethanes, etc. [19]. 

V,V dimethyl acetamide Ethylene-vinylacetate copolymer Hour... 

More recently, somewhat incompatible systems with a-methylstyrene copolymers, ethylene-vinylacetate resins, and paraffin wax (13) have shown exceptional hot tack although the blend is clearly incompatible. Table III shows that the adhesion increases with the cloud point of the blend. 

Films. Three films were included in this study. Low density polyethylene (LDPE) was included as a representative polyolefin. It is not considered to be a barrier polymer. It has permeabilities to selected aroma compounds slightly higher than the permeabilities of polypropylene and high density polyethylene (1). A vinylidene chloride copolymer (co-VDC) film was included as an example of a barrier that is useful in both dry and humid conditions. The film was made from a Dow resin which has been designed for rigid packaging applications. A hydrolyzed ethylene-vinylacetate copolymer (EVOH) film was included as an example of a barrier film that is humidity sensitive. The polymer was a blend of resins with total composition of 38 mole% ethylene. 

The ESD behavior can be provided by blending in a flexible-chain polymer with an active -OH or -SH group, viz. polyvinyl alcohol (PVAl), ethylene-vinylacetate (EVAc), polyvinylphenol (PVPh), a copolymer of ethylene oxide and epi-chlorohydrin (EO-CHR), maleated copolymer, aliphatic polysulfides, etc. These low performance resins have been incorporated into a variety of alloys and blends (see Table 1.79). 

The theory was found to predict complex behavior near the phase separation conditions. As the rate of shear increases, first, the system undergoes homogenization, then demixing, followed by another homogenization and demixing. At high rates of shear, the system should behave similarly as in a quiescent state. These predictions were found to be in qualitative agreement with experimental data, e.g., for blends of ethylene-vinylacetate copolymer with chlorinated polyethylene, EVAc/CPE, or polystyrene with poly(vinyl methyl ether), PS/PVME [Hindawi et al., 1992 Eernandez ef fl/., 1993, 1995]. 

Ethylene-vinylacetate blends with PVC have been widely used in Europe as permanent polymeric plasticizers for PVC. Low cost and good weatherability of these blends permitted their use in window profiles, cable jacketing and other outdoor applications. Ethylene vinylacetate copolymer with 65-75% vinyl acetate content is quite miscible with PVC exhibiting a single T for the blend [Hammer, 1971 Ranby, 1975 Rellick and Runt, 1985]. Two phases are apparent when the vinylacetate is < 45%. Vinylchloride grafted ethylene-vinyl acetate copolymers have also been used for blending with PVC. 

E-BA-CO E-VAc-CO (Ethylene-n-butylacrylate-carbon monoxide ethylene-vinylacetate-carbon monoxide)... 

Roumen, F.J.M.E. and T.O.M. Dieben, Clinical acceptability of an ethylene-vinylacetate nonmedicated vaginal ring. Contraception, 1999, 59(1), 59-62. 

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