Establishment and verification of curing kinetics model of 603 epoxy resin system

The curing kinetics of 603 thermoplastic toughened epoxy resin was investigated by non-isothermal differential scanning calorimetry (DSC). The curing reaction of 603 epoxy resin system was consisted of two dominant reactions (reaction 1 and 2), as evidenced by the presence of a double peak on the DSC thermograms. The curing kinetics of the 603 resin system was investigated after separating the two overlapping exothermic peaks. The overall apparent activation energies of the curing processes were fitted respectively with Kissinger method and a two-parameter (m, n) Kamal model was employed to describe the curing kinetics. The reliability of established model was proved by comparing the calculation results with the experimental results of three different curing processes of the epoxy resin system. Based on the exothermic curves at different heating rates, the curing temperature of the reaction 1 whose heat accounted for 70% of the total heat of reaction is (177.3±2.2)℃ and the initial temperature and the curing temperature of the reaction 2 whose heat accounted for 30% of the total heat of reaction are (178.6±0.7)℃ and (216.9±1.7)℃ respectively by extrapolation method. The results have important significance for the analysis of curing kinetics of multi-component thermosetting resin system and optimization of composite processing.