Synthesis and properties of bromide‐ functionalized poly(isobutylene‐ co‐p ‐ methylstyrene) random copolymer

Poly(isobutylene‐ co‐p ‐methylstyrene) ( IB / p ‐ MS ) random copolymer is a new generation of polyisobutylene‐based elastomers. The cationic copolymerization of IB with p ‐ MS was thoroughly examined by using 2‐chloro‐2,4,4‐trimethylpentane/ethylaluminiumsesquichloride/electron donor as initiating system. IB / p ‐ MS random copolymers with high molecular weight were obtained at elevated temperature through the addition of ethyl acetate; the reaction proceeded in a mildly exothermic manner. Although the reactivity ratios of comonomer pairs differ by close to an order of magnitude, p ‐ MS was uniformly distributed in the chains. IB / p ‐ MS random copolymer can be brominated by adding molecular bromine into the copolymer solution, thereby yielding a completely saturated polymer backbone with a chemically reactive site. The types and selection of appropriate vulcanization systems for bromide‐functionalized IB / p ‐ MS random copolymers are also discussed. © 2016 Society of Chemical Industry