. . "al groups, such as halogen atoms, are introduced in high yield at the terminal ends of the polymer chain.DETAILED DESCRIPTION OF THE INVENTIONThe cationic polymerizable monomer containing isobutylene usable in the present invention is a monomer consisting solely of isobutylene or a mixture of isobutylene and a cationic polymerizable monomer copolymerizable with isobutylene." . .