Copolymers of anionic polymerization of octanelactam with laurolactam (nylon-8/12 copolymers)-I. Preparation and general properties

Abstract

Thermoplastic statistical copolyamides from nine mixtures of octanelactam (OL) and ω-laurolactam (LL) and also the corresponding homopolymers (nylon-8 and nylon-12) were obtained in high yields by activated anionic copolymerization at 180°C, using sodium hydride as catalyst and N-phenylcarbamoylcaprolactam as activator. The proportions of co-units in the copolymers (freed from oligomers) were determined by elemental analysis, u.v. spectroscopy and NMR. Samples were also characterized by Tm, [n], d(g/cm3), Mn (osmotic), amino-end groups content and interplanar spacing (X-ray). The results are correlated with the molar ratio of the comonomers (OL/LL) and discussed. Minima for Tm and crystallinity were indicated for the copolymers of 50 50- 60 40 OL/LL molar compositions. © 1990.