Decay of catalytic activity during the cationic polymerization of capryllactam

Abstract

At lower concentrations of initiator and temperatures above 200°C, the polymerization of capryllactam initiated by hydrogen chloride is characterized by two kinetically different stages: the initial rapid growth becomes considerably slower due to the fast transformation of the original growth centers into amidines. The steep decrease in molecular weight during hydrazinolysis indicates that the amidine groups are also present inside polymer molecules. The formation of these structures may be explained by condensation of the amino endgroups with the amide or acyllactam groups.

A comprehensive model for nylon melt equilibria and kinetics

“…at 220ЊC with initial water contents between 0. 15 The coupling of the dielectric constant to reacwt % and 0.6 wt %, 22 polymerization of caprolaction rate relates to some polyamide steady-state tam at 235, 245, 255, and 265ЊC with an initial phenomena as well. Because water content of 2 wt %, 6 nylon 7 hydrolysis, 6 and caprolactam polymerization experiments between 230 and 270ЊC with initial water contents be-…”

“…(1)] is no Sebenda, 15 who studied a series of nylons (2-11) longer sufficient. Instead, the following two reacand found for the higher nylons (nylon 8/) the tions are assumed to occur, and the equilibrium molecular structure would absorb about 0.5 moleis calculated based on these (because enthalpy cules of water per amide group in the amorphous and entropy are state functions, the kinetic path region.…”