Anionic Copolymerization of e-Caprolactam with co-Laurolactam

Starting with a functionaUzation of a,(o-dihydroxy-terminated poly(ethylene oxide) or poly(propylene oxide) by HDl 18, followed by a reaction with a,(0-diamino-terminated copolymer of butadiene and acrylonitrile, a triblock macroactivator was synthesized the anionic polymerization of CL at 140 °C in the presence of this copolymer gave an A-B-C-B-A copolymer [61]. A similar macroactivator for block copolymer synthesis was prepared by a stepwise anionic polymerization of isoprene (with dilithium a-methylstyrene tetramer) and oxirane [62]. 

When trifunctional polybutadiene prepared by a radical polymerization was incorporated (to the extent of 2-20 wt%) into the PA 6 matrix at 180°C, using a functionalization by IP 22 and HDl 18 [63], surprisingly, the toughness was markedly increased for a low, built-in PBD concentration of only 2wt%. 

When using decaline as solvenL a macroinitiator based on a hydrogenated PBD was used as a starting substance for block copolymer preparation which was functionalized by bis(carbamoyllactams) under the catalysis of NaH [64]. 

An elegant assessment of the stability of bonding of the growth center to polymer (i.e. the stability of the macroactivator) was made by following the alcoholysis and aminolysis of N-acyUactams and N-substituted carbamoyl lactams [65, 66]. 

Currently, research into anionic copolymerization is focused on the pair e-caprolactam (CL)/co-laurolactam (LL)-that is, industrially available lactams. A number of other pairs of lactams have been described [7, 11, 67]. 

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