Polyamides from lactams by centrifugal molding via anionic ring-opening polymerization

This paper deals with a study of some properties of the polymers obtained b y centrifugal molding via activated anionic ring-opening polymerization of epsilon -caprolactam and copolymerization of epsilon -caprolactam with laur olactam. Ethyl magnesium bromide, as initiator and N-benzoyl epsilon -capro lactam and N,N'-isophrhaloyl-bis-epsilon -caprolactam, as activators were u sed. The initial mold temperature (initial polymerization temperature) was kept constant at 160 degreesC. Our experimental data demonstrated that the degree of crystallinity depends on the activator type and concentration. Th e incorporation of laurolactam into nylon 6 chain depresses both in the deg ree of crystallinity and the melting temperature of nylon 6/12 copolymers. The notched Izod impact strength of the copolymers increased as the laurola ctam content was increased, while the flexural modulus and the water absorp tion decreased. (C) 2001 Elsevier Science Ltd. All rights reserved.