Curable copolymers of isobutylene and acrylic ester

Curable copolymers of isobutylene and acrylic ester were successfully synthesized by incorporation of a third monomer into alternating copolymers of isobutylene and acrylic ester by means of complexed copolymerization catalysed with alkylboron halide. As the third monomer, acrylic ester including an unsaturated bond in the ester group (AEU), such as crotyl acrylate, or vinyl monomer including a chlorine atom (CVM), such as 2-chloroethyl vinyl ether, was effectively incorporated. The terpolymers containing AEU (AIDM) were easily vulcanized with sulfur. The terpolymers containing CVM (AICM) were sufficiently well cured with polyamine. The cured products of both AIDM and AICM had excellent properties in terms of oil resistance, water resistance and others. The blend of AIDM and ethylene-propylene-diene rubber was satisfactorily co-vulcanized with sulfur.