EXPANDABLE VINYL AROMATIC POLYMERS AND PROCESS FOR THE PREPARATION THEREOF

摘要

The present invention is an expandable vinyl aromatic polymer which comprises: a ) a matrix of a branched aromatic ionomer, b ) 1 -10% by weight calculated with respect to the polymer (a), of an expanding agent englobed in the polymeric matrix, c ) 0-20% by weight, calculated with respect to the polymer (a), of a filler homogeneously distributed in the polymeric matrix, in which, the branched aromatic ionomer comprises the product of co-polymerizing a first monomer comprising an aromatic moiety and an unsaturated alkyl moiety and a second monomer comprising an ionic moiety and at least two unsaturated moieties, wherein the ionic moiety has at least two ionizable groups, a cationic group that ionizes to form cations and an anionic group that ionizes to form anions, and wherein the cationic group is polyvalent and one capable of forming bridges to other molecules. The present invention also relates to the use of the expandable vinyl aromatic polymer to make expanded articles, in particular insulation boards.