a cross - linked composition produced by exposing a mixture including a telechelic polyisobutylene - containing base polymer which carries multiple terminal acrylate groups as a part thereof , a reactive diluent , and in some cases , a high - energy sensitizer , to high - energy radiation . the base polymer may also comprise a block copolymer which has polyisobutylene , and polydiene blocks as , for example , polyisoprene , and in which the polydiene blocks , advantageously partially cyclized , carry multiple acrylate groups as a part thereof . among other things , the compositions have particular application in the formation of films useful in the electronic , biomedical , specialty adhesive , sealant , and other fields .