Insights into anhydride-cured epoxy resin system using dynamic chemo-rheological modeling

Anhydride-cured epoxy resin is preferred over its contemporary because it is less poisonous, produces reduced heat during curing, and exhibits lower curing shrink-age. Hence, this work helps to understand the curing process of the mentioned resin. The non-isother mal chemo-rheological behavior of the anhydride-cured epoxy resin system is investigated by performing differential scanning calorimetry and rheom-etry at five different heating rates: 1 degrees C/min, 2 degrees C/min, 5 degrees C/min, 8 degrees C/min, and 10 degrees C/min. Gelling time found using DSC and rheology are comparable. Activa-tion energies (E-a) and other cure parameters are determined by the iso-conversional KAS, FWO, Friedman, and model-free Kissinger's approach, and the average values are compared. Dependencies between E(a )and degree of conversion (alpha) describe the complex cure process of the epoxy resin system. The activation energy trends indicated that the cure reaction follows two phases: cure kinetics controlled, and diffusion is the controlling factor in the second phase. Furthermore, the Arrhenius viscosity model is used to predict the viscosity profile during non-isothermal curing. The predicted viscosity model significantly agrees with the experimental data and correlates kinetics with the complex viscosity of the epoxy resin.