Olefinic copolymers Ethylene-vinyl chloride

As reported by Diehl et al. [58], interpolymers are also compatible with a broader range of polymers, including styrene block copolymers [59], poly(vinyl chloride) (PVC)-based polymers [60], poly(phenylene ethers) [61] and olefinic polymers such as ethylene-acrylic acid copolymer, ethylene-vinyl acetate copolymer and chlorinated polyethylene. Owing to their unique molecular structure, specific ESI have been demonstrated as effective blend compatibilizers for polystyrene-polyethylene blends [62,63]. The development of the miscibility/ compatibility behavior of ESI-ESI blends differing in styrene content will be highlighted below. 

As mentioned previously, the Alfrey Priee Q and e values for vinyl acetate are 0.026 and —0.22, respectively [226]. Thus vinyl acetate is rather sluggish in its free-radical copolymerization, with most monomers, particularly olefinic monomers, bearing electron-donating subtitutents. The copolymerization reactivity ratios reflect the reluctance of vinyl acetate to enter into copolymerization with other monomers [270]. Nevertheless, vinyl acetate copolymers with a great many electron-rich as well as electron-poor olefins have been prepared. Especially significant from a commercial point of view are copolymers with ethylene, vinyl chloride, acrylates, methacrylates, fumarates, and maleates. Often, mixtures of three and more comonomers are used in these copolymerizations. 

For example, this method was carried out for various copolymers, namely styrene-methyl methacrylate copolymer [65-67], epoxide resins [68], styrene-acrylic acid copolymer [69], styrene-2-methoxyethyl methacrylate copolymer [70, 71], ethylene-ot-olefin copolymer [72], partially modified dextran-ethyl carbonate copolymer [73], vinyl chloride-vinyl acetate copolymer [43], styrene-acrylonitrile copolymer [74], and styrene-butadiene copolymer [75]. 

Materials that can be used as main components of thermoplastic adhesives are vinyl acetate, polyvinyl alcohol, polyvinyl acetal, ethylene-vinyl acetate copolymer (EVA), vinyl chloride, acrylic resin, polyamide, cellulose, alfa-olefin resin, and waterborne isocyanate resin. 

Amongst copolymers of PE, there are polyallomers (ethylene-propylene copolymers), copolymers with cyclo-olefins and with vinylic monomers [with vinyl acetate ethylene-vinyl acetate, (EVA), with methacrylic acid, MA, and with vinyl alcohol ethylene - vinyl alcohol, (EVOH)], and chlorinated PE (CPE). CPE, although it exhibits exceptional UV and chemical resistance, gives rise to a high amount of hydrogen chloride gas evolution if combusted. 

Influences due to steric hindrance are mostly swamped by those due to polarity and resonance stabilization. For example, 1,2-disubstituted ethylene monomers form random copolymers with comonomers of similar polarity, i.e., dimethyl fumarate/vinyl chloride. If the polarities differ greatly, even alternating copolymers can be formed because of the formation of CT complexes, as, for example, with maleic anhydride/styrene (see also Section 22.3). Even two 1,2-disubstituted monomers copolymerize with each other if the polarities differ very greatly, as happens with, for example, maleic anhydride and stilbene, since the polar interaction in the transition state helps to overcome the steric hindrance. Threefold substituted olefins produce an additional stabilization without steric hindrance in the transition state, and so can be easily copolymerized with comomoners of opposite polarity. 

Alcryn Chlorinated olefin/EVAl/acrylate ester blends PVC/ethylene-carbon monoxide-vinyl chloride copolymer TP elastomers E. I. du Pont de Nemours... 

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