Cationic polymerizations by aromatic initiating systems. V. Oxidation and chlorination of α,ω-diphenylpolyisobutylene and subsequent reaction with living polystyrene anions to form block copolymers

α,ω-Diphenylpolyisobutylenes produced by the Cl^t-R-Cl^t/ø₃Al initiating system have been derivatized. Model chloromethylation of t-butylbenzene by CH₃OCH₂Cl in chloroform indicated that beyond ca. 35% yield significant alkylative side reactions occurred. Phenyl end groups (average 1.5 per chain) and unsaturated chain ends (from proton elimination) have been converted to carboxyl end groups by oxidation with RuO₄ in chloroform. Subsequently the carboxyl end groups were converted to acyl chloride termini by reaction with SOCl₂. The latter end groups were coupled with living polystyryl anions to form isobutylene-styrene blcok copolymers.