Block copolymers containing isobutylene

Radicalic polymerized block copolymers containing poly(isobut-ylene) and poly(p-chlorostyrene) have been described as compatibilizers (40). Similarly, copolymers containing poly(isobutylene) and p-ferf-butylstyrene are useful compatibilizers for olefinic elastomers (2). 

Improved polyurethane can he produced hy copolymerization. Block copolymers of polyurethanes connected with segments of isobutylenes exhibit high-temperature properties, hydrolytic stability, and barrier characteristics. The hard segments of polyurethane block polymers consist of 4RNHCOO)-n, where R usually contains an aromatic moiety. 

Treatment of polyisobutylene (which contains terminal double bonds) with ozone followed by thermolysis produces polymeric radicals. Isobutylene-styrene block copolymer is formed when thermolysis is performed in the presence of styrene, but the process is not efficient because polystyrene and polyisobutylene homopolymers constitute more than half of the product [Cunliffe et al., 2001]. 

Isobutylene and alloocimene (1.6-2.8 mol%) have been copolymerized with EtAlCl2 as the catalyst in n-heptane/methyl chloride 1 1 (v/v) solution at -70°C. The resulting linear copolymers had block-like structures and MWs in the range of 145-260 kg/mol (no PDI given). In contrast to the previous examples, the copolymer contained only traces of alloocimene units with conjugated unsaturation [46],... 

Isobutylene was copolymerized with methylbenzenes by cationic methods to give products containing 1-2% of the comonomer. Attachment of polyplvalolactone grafts was accomplished using the same chemistry as that for Isoprene block-graft copolymers. 

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