POLYVINYL CHLORIDE

(PVC) a synthetic resin belonging to the family of polymeric organic compounds, manufactured by treating vinyl chloride (q.v.) with a peroxide catalyst, usually in aqueous suspension or emulsion. After mixing with plasticizers, stabilizers, and pigments, the resin may be fabricated by techniques such as calendering, molding, or extrusion into flexible articles such as raincoats, shower curtains, and packaging films. The resin is not plasticized for use in making rigid products such as water pipe, plumbing fittings, and phonograph records. For use in making piping or structural panels that require high resistance to impact, polyvinyl chloride often is blended with small proportions of rubbery synthetic polymers. Resins more easily plasticized than polyvinyl chloride can be prepared by adding various proportions of vinyl acetate to vinyl chloride before polymerizing the mixture; stiffer resins result from treatment of polyvinyl chloride with chlorine.