Hydrogenated vinyl aromatic polymer foams

Abstract

This invention provides a thermoplastic polymer foam having a density of up to 800 kg/m3. The foam is made from a hydrogenated vinyl aromatic polymer that contains pendant cycloaliphatic groups. This polymer is conveniently made by hydrogenating a poly(vinyl aromatic) polymer such as polystyrene or a polystyrene-butadiene block copolymer. A suitable blowing agent is a mixture comprising (a) one or more fluorine-containing carbon compounds and (b) carbon dioxide, nitrogen, an alcohol having from 1 to 4 carbon atoms, a linear or cyclic hydrocarbon having from 1 to 6 carbon atoms, a ketone, an alkyl ether, an alkyl halide, water or a mixture thereof.

Dependencies are inferred from the claim text.