Modeling of curing and post-curing kinetics for a thermoset adhesive

Abstract

The properties of adhesives cured at low temperatures are often significantly affected by post-curing effects. This paper introduces a method to model both the curing and post-curing kinetics for thermoset adhesives. The total and residual enthalpies and the glass-transition temperature (Tg) of the adhesive were measured via differential scanning calorimetry. The obtained degree of cure (DOC) and Tg were then fitted to determine their functional relationship. Low-temperature curing experiments were conducted, and an nth-order curing kinetics equation was developed through the fitting of data. Post-curing experiments were performed on samples with varying initial DOCs, and the resulting post-curing data were normalized and fitted using an nth-order model. The relationships between the kinetic parameters and the initial DOC, post-curing temperature and time were analyzed, and a comprehensive kinetics model crossing the curing and post-curing stages was successfully established. Model validation was carried out, and the results demonstrated a good predictive capability.