KINETICS OF ADIABATIC ANIONIC COPOLYMERIZATION OF EPSILON-CAPROLACTAMIN THE PRESENCE OF VARIOUS ACTIVATORS

Adiabatic temperature rise has been recorded as a function of polymeri zation time to investigate an adiabatic copolymerization kinetics of e psilon-caprolactam (CL) in the presence of several activators, conside ring different initial copolymerization temperatures ranging from 130 to 160 degrees C. The copolymerization of CL and PEG-diamine has been performed using activators such as tolylene dicarbamoyl dicaprolactam (TDC), hexamethylene dicarbamoyl dicaprolactam (HDC), and cyclohexyl c arbamoyl caprolactam (CCC), and sodium caprolactamate as a catalyst. T he effect of PEG-diamine on the overall rate of polymerization of CL h as been studied by fitting the experimental temperature rise with a ne w polymerization kinetic equation involving the polymerization exother m, polymerization-induced crystallization exotherm, and the heat loss due to nonideal adiabatic condition in the experimental situation. Lik e homopolymerization, the net copolymerization rate is influenced by t he variation of activator types in the initiation step. The temperatur e rise due to polymerization-induced crystallization in copolymerizati on is drastically decreased with the increasing initial polymerization temperature in the course of polymerization. The high molecular weigh t and large polydispersity index of copolymers using bifunctional acti vators indicate that the Claisen type condensation can occur in the co urse of polymerization processes. (C) 1997 John Wiley & Sons, Inc.