Polystyrene-polybutadiene block copolymers prodn - by block copolymsg. butadiene and styrene onto living poly-alpha-methyl styrene block, with good thermal stability

摘要

Thermally stable block copolymers of the type ABC, where A is a poly-alpha-methyl styrene block, B is a polybutadiene block and C is a polystyrene block are made by polymerising the alpha-methyl-styrene either in the mass or in a hydrocarbon soln, using a concn of not less than 50 wt.% in the presence of sec. butyl lithium at a temp. of 0-50 degrees C whereby a living block A is produced onto which a diene hydrocarbon block and styrene is polymerised at 40-80 degrees C.