Chloride-containing vinyl acrylic latex copolymers

Free-radical copolymerizations can be carried out by any one of the usual methods used for the preparation of the homopolymers themselves. Particularly advantageous for the synthesis of these copolymers are emulsion copolymerizations [271]. Separate emulsions each containing one, two, or more monomers can be equilibrated with one another and then polymerized to give the copolymer latex. Random ethylenevinyl acetate copolymers, which have found considerable commercial use in adhesives, coatings, and molding compounds are prepared by various techniques. Those polymers that have high ethylene contents are normally prepared by bulk or solution methods while high-pressure emulsion techniques are employed for copolymers rich in vinyl acetate [272]. Vinyl acetate is often polymerized in minor amounts with vinyl chloride and with acrylic monomers to modify their polymers and to impart special properties, such as plasticization and dyeability. 

Copolymerization. Vinyl chloride can be copolymerized with a variety of monomers. Vinyl acetate, the most important commercial comonomer, is used to reduce crystallinity, winch aids fusion and allows lower processing temperatures. Copolymers are used in flooring and coatings. This copolymer sometimes contains maleic add or vinyl alcohol (hydrolyzed from the poly(vinyl acetate ) to improve the coating s adhesion to other materials, including metals, Copolymers with vinylidene chloride are used as barrier films and coatings. Copolymers of vinyl chlonde with acrylic esters in latex from are used as film formers in paint, nonwoven fabric binders, adhesives, and coatings. Copolymers with olefins improve thermal stability and melt flow, but at some loss of heat-deflection temperature,... 

MAJOR APPLICATIONS Homopolymer and copolymers—usually with vinyl chloride (VC), or methyl acrylate (MA)—used in solvent-based or latex barrier coatings on cellophane, paperboard, plastic film, and rigid food containers. Films of copolymer used as household cling wrap. Also used with other polymers in multilayer barrier films or containers mostly in packaging applications. Also used in fibers and adhesives. 

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