Abstract

Monomers (both monoolefinic and diolefinic) containing the bicyclo[2.2.1] heptene system copolymerize with ethylene and propylene by opening the double bond of the endo-methylenic system without rupture of the bicycloheptene system itself. Therefore, only diolefinic monomers produced unsaturated terpolymers. The rate of ethylene-propylene-dicyclopentadiene terpolymerization and the relative reactivity of ethylene and propylene are influenced by the concentration of dicyclopentadiene present in the liquid phase. The rate of vulcanization of ethylene-propylene-dicyclopentadiene terpolymers is slower than that of the other synthetic elastomers (butyl rubber, ethylene-propylene-cyclooctadiene-1,5 terpolymer).