Anionic block copolymerization of ϵ-caprolactam

?-Caprolactam anionic homopolymerization was studied in the presence of different model activators. On the basis of the results ester- and isocyanate-terminated polymers were used as macroactivators and nylon-6–polyvinyl or polydiene block copolymers were synthesized in high yields. The physical properties and morphology of a nylon–polybutadiene triblock copolymer were characterized.