Miscellaneous Vinyl Thermoplastics

The most important vinyl polymers have been discussed in separate chapters. Other commercial vinyl polymers, which have more limited or very specialist applications, are discussed in this chapter. Vinylidene chloride is unstable, and is normally used in the form of a copolymer with vinyl chloride (typically 15%), but also with acrylates, methacrylates, or acrylonitrile. The copolymers have excellent barrier properties so are used extensively in packaging films. Poly(vinyl acetate) is mainly used in emulsion paints and adhesives, but is also converted into poly(vinyl alcohol) used for various applications, including adhesives, fibers, and recently in injection-molded products. Poly(vinyl formal) is mainly used as a wire enamel and in other coating applications, in conjunction with a phenolic resin, while poly(vinyl butyral is well known as a safety glass interlayer. Ethylene vinyl alcohol copolymers are widely used as barrier films for packaging applications. Poly(vinyl cinnamate) and poly(vinyl carbazole) are considered briefly.