One-Pot Synthesis of Polyamide 12,T-Polyamide-6 Block Copolymers

Theodore F. Novitsky, University of Southern Mississippi
Lon J. Mathias, University of Southern Mississippi

Abstract

Polyamide 12, T-polyamide-6 (PA-12, T-PA-6) block copolymers were synthesized by anionic polymerization of caprolactam using a PA-12, T macrocoinitiator (McI). PA-12, T McI and its precursors are soluble in molten caprolactam allowing for both the McI step-growth polymerization and anionic polymerization to be performed in one-pot. It was found that the competing reaction rates of caprolactam ring-opening polymerization and McI transamidation are both deterred by a common ion effect using CaCl(2) and soluble materials were obtained using > 1 mol % CaCl(2). Without CaCl(2), the reaction mixture solidifies in less than 30 s and produces crosslinked materials. To understand this effect, PA-12, T McI reactions with caprolactam were performed with 1-10 mol % CaCl(2), and polymer structures were characterized using (13)C NMR and dilute solution viscometry. These data were then correlated with unique thermal properties and swelling behavior of the block copolymers. (C) 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 49: 2271-2280, 2011