Synthesis and characterization of star-branched polyamide 6 via anionic ring-opening polymerization with N,N′, N"-trimesoyltricaprolactam as a multifunctional activator

Star-branched polyamide 6 was prepared via anionic ring-opening polymerization of a-caprolactam in the presence of a simple benzene-centered trifunctional activator of N,N',N ''-trimesoyltricaprolactam. A high polymer yields of above 95% were achieved at 160 degrees C for 15 min utilizing epsilon-caprolactam magnesium bromide as a catalyst. Compared with its linear counterpart, the resultant star-branched polyamide 6 showed smaller relative viscosity (1.51), decreased melting temperature (218 degrees C) and lower crystallinity (24.2%). The specific properties demonstrated the existence of a star-branched structure and provided potential advantages in engineering applications. (C) 2015 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.