Kinetics of solid-phase prepolycondensation of demonomerized polycaproamide

Abstract

A variant of solid-phase prepolycondensation of PCA that takes place in conditions of an irreversible reaction is examined and a relation that satisfactorily describes the kinetics of the process in the case of an excess of terminal groups of one kind in the polymer is obtained. It was found that passage of solid-phase prepolycondensation of PCA from conditions of a reversible to conditions of an irreversible reaction is accompanied by an almost two-fold increase in the kinetic nonequivalence parameter of the reaction sites while the maximum rate constant remains almost unchanged. It is shown that at 453–483 K, depolymerization of demonomerized PCA takes place at a rate which is low in terms of the decrease in the yield of polymer, but is relatively high from the point of view of the necessity of recovering the caprolactam separated.