Introduction of polymerizable group at both ends of polyester and synthesis of network polymer containing polyester

Abstract Base-catalyzed transesterification of cyclic polyester with diglycidyl phthalate affords polyester with an epoxy group at both ends, while similar transesterification with bis(4-vinylbenzyl) phthalate affords polyester with a styryl group at both ends. These polyesters work as cross-linkers. Polyester-network-containing polystyrene gel, obtained by the radical copolymerization of styrene and the latter cross-linker, is converted to a soluble polymer by transesterification with poly(ε-caprolactone).