Simulation of solid-state polycondensation of nylon-66

A new model of solid-state polymerization of nylon-6,6 has been developed. The polymer crystalline fraction is assumed to consist of only repent units , leaving end-groups and condensate in the amorphous fi action. Many effect s neglected by previous models are considered such as variable crystallinit y, initial moisture and starting molecular weight. This model is compared t o experimental data with good agreements. Differential scanning calorimetry graphs show that Me crystalline structure phase tends to be increasingly p erfect during heat treatment, indicative of the premelting temperature draw ing near the melting point up to 14 degrees C after solid-state polycondens ation with little change of melting point. Copyright (C) 2000 John Wiley & Sons, Ltd.