Ethylene/propylene/5-ethylidene-2-norbornene

Summary Ethylene/propylene/5-ethylidene-2-norbornene(ENB) terpolymerization was carried out with a highly active Ti catalyst system(MgCl₂/TiCl₄/C₆H₅COOC₂H₅ (EB) — AliBu₃/di-iso-amyl ether (IAE)). The obtained terpolymer could be vulcanized with sulfur, but the increase of torque value through the vulcanization measured by curelastometer for the terpolymer obtained with this catalyst was considerably lower than that for the terpolymer obtained with the conventional VOCl₃ catalyst system. It was suggested that lower torque value would be attributed to the heterogeneous diene distribution in the obtained terpolymer, particularly lower ENB content in the high molecular weight fraction.