DESCRIPTION

Isobutylene–Isoprene Copolymer occurs as a synthetic copolymer containing from 0.5 to 3.0 molar percent of isoprene, the remainder consisting of isobutylene. It is prepared by copolymerization of isobutylene and isoprene in methyl chloride solution, using aluminum chloride as the catalyst. After completion of polymerization, the rubber particles are treated with hot water containing a suitable food-grade deagglomerating agent, such as stearic acid. Finally, the coagulum is dried to remove residual volatiles.