SYNTHESIS OF ABA TRIBLOCK COPOLYMERS OF STYRENE AND P-METHYLSTYRENE BY LIVING CATIONIC POLYMERIZATION USING THE BIFUNCTIONAL INITIATING SYSTEM 1,4-BIS(1-CHLOROETHYL)BENZENE SNCL4 IN THE PRESENCE OF 2,6-DI-TERT-BUTYLPYRIDINE/

ABA triblock copolymers of styrene and p-methylstyrene were prepared b y living cationic polymerization using a bifunctional initiating syste m in the presence of 2,6-di-tert-butylpyridine, which, as a proton-tra pping agent, suppressed the initiation by adventitious impurities and thus enhanced the Livingness of the styrene monomers. By using these c haracteristics, triblock copolymers of styrene and p-methylstyrene cou ld be prepared easily. The polymers showed the same molecular weight a s the theoretical value and narrow and unimodal molecular weight distr ibutions (MWDs).