Abstract: A blend is provided which is suitable for preparing low density cellular products of the closed cell type, said blend comprising a vinyl chloride resin, e.g., polyvinyl chloride; a butadiene rubber, e.g., butadiene-acrylonitrile; and a liquid polyfunctional or monofunctional monomer, e.g., styrene. Insulation products such as sheets or tubes (for pipe insulation) are easily fabricated by freely expanding (i.e., without employing forming molds) blends of the invention which contain heat-activatable blowing agents.

Abstract: The propensity of poly(vinyl chloride) homopolymer and poly(vinyl chloride) copolymer resin-containing compositions including poly(vinyl chloride) modified rubbers to smoke on exposure to fire is greatly diminished by the addition of effective amounts of ferric oxide. Amounts in excess of about 5%, based on the weight of the poly(vinyl chloride) resin or poly(vinyl chloride) modified resin or rubber, act as an effective smoke suppressant. Additionally, the combination of ferric oxide with hydrated metallic compounds results in poly(vinyl chloride) homopolymer and copolymer-containing compositions having both low smoke and low flame spread characteristics.