|Development of Isobutylene Based Rubbers\Butyl Rubbers and Others\
Polymers Department, ExxonMobil Yugen Kaisha., Tokyo
Nippon Gomu Kyokaishi,(2005),78(2),78-80 General Review in Japanese
Isobutylene based rubbers have unique property such as impermeability to air and various gases. Main product of isobutylene based rubbers is butyl rubber, which was commercialized about 60 years before and has been used mainly for tire innertubes. Halobutyl rubbers were invented and enabled co-cure with natural rubber. The halobutyl rubbers are used mainly in tire innerliner application. To further meet market/customer requirements to butyl rubbers in various applications, star-branched butyl rubbers were developed mainly to improve processability of butyl rubbers with bimodal molecular weight distribution including star shape molecules as high molecular weight portion. And brominated isobutylene-co-p-methylstyrene rubbers of which ozone and heat resistance were improved by the saturated backbone and cross-linking chemistry, respectively, were also commercialized. Both star-branched butyl and brominated isobutylene-co-p-methylstyrene rubbers maintain attributes of butyl rubbers.
Isobutylene based rubbers, Air impermeability, Star-branched butyl rubbers, Bimodal molecular weight distribution, Brominated poly(isobutylene-co-p-methylstyrene), BIMS