SELF-CURING BEHAVIORS OF SINGLE PACK AQUEOUS-BASED POLYURETHANE SYSTEM

A di- or triaziridinyl compound served as the latent curing agent for the prepared carboxylic groups containing aqueous-based polyurethane ( PU) dispersions. It was formulated as a single pack self-curable aqueo us-based PU system. This system was stable under an alkaline environme nt and its curing reaction could be initiated by a pH control. A model reaction between a monoaziridinyl compound and formic acid was demons trated and identified by infrared spectrophotometry. The stabilities o f this convenient one-package PU system with a different dosage of di- or triaziridinyl latent curing agent were monitored by a particle siz er and fluorescence spectroscopy. The PU films were cast and self-cure d from these single pack PU dispersions at ambient temperature. The ph ysical and mechanical properties as well as thermal behaviors of each self-cured PU were evaluated. (C) 1997 John Wiley & Sons, Inc.