Block copolymers of hexano-6-lactam with N-methylated aliphatic (co)polyamides

Diblock copolymers consisting of poly(hexano-6-lactam) hard blocks and high ly N-methylated (or N-ethylated) softer blocks of poly(dodecano-12-lactam) or poly(octano-8-lactam) were prepared by anionic polymerization of hexano- 6-lactam initiated with diacylamine branching sites of multifunctional prec ursors of polymeric initiators (PPI). The PPI were prepared by the acidolyt ic copolymerization of the respective N-alkylactams (greater than or equal to 90 mol %), N-benzoyllactams (less than or equal to 5 mol %) and lactams (less than or equal to 5 mol %). The method provides diblocks accompanied b y small amounts of the homopolymers. The PPI and block copolymers were char acterized by H-1 NMR, imide and carboxyl group analysis, viscosity, SEC, DS C, mechanical properties and water sorption. (C) 2000 Elsevier Science Ltd. All rights reserved.