| abstract |
Extruded expanded substantially gel and cross-link free rigid vinyl chloride polymer articles are prepared from mixtures of high molecular weight vinyl chloride polymers and copolymers of a styrene and an acrylonitrile or alkyl methacrylate, optionally with a polymer of butadiene, styrene and acrylonitrile, and a blowing agent, without the use of plasticizers, solvents or cross-linking agents. In extruding these compositions, sized pipe, bottles, boards and the like are readily prepared having fine, uniform, cell structure, hot strength, and specific gravities from about 0.38 to 0.95. |