A novel catalytic system—NdCl3 · HMPA/AI(i‐6u)3 for copolymerization of isoprene and styrene

Co polymerization of styrene (St) and isoprene (IP) was carried out with a catalyst system composed of anhydrous lanthanide chloride hexamethyl phosphor amide complex (LnC1₃‐HMPA) and aluminum organic compound (AOC). Among the catalysts examined, catalyst NdC1₃*HMPA/Al(i‐Bu)₃ showed a high activity in the copolymerization under certain conditions giving copolymers (5%‐158 St content) with high cis‐1, 4 microstructure in IP Units (>95%). The effects of HMPA/Nd molar ratio, Al/Nd molar ratio, monomer/Nd molar ratio, St feed ratio, and the reaction time on copolymerization were examined with this catalytic system. The obtained copolymers were characterized by ¹H and ¹³C NMR spectroscopies and gel‐permeation chromatography (GPC).