A Study on the Selection of Cure Kinetics Models for Predicting the Curing Behavior of Epoxy Resins

Carbon Fiber Reinforced Plastics (CFRP), known for their excellent specific strength, stiffness, and heat resistance, are key structural materials in aerospace, automotive, and defense industries.Especially in propulsion systems under extreme environments, understanding the curing behavior of the epoxy matrix is crucial for reliability.In this study, the curing behavior of the epoxy resin applied to CFRP was quantitatively analyzed under both isothermal and non-isothermal conditions using Differential Scanning Calorimetry (DSC).Under isothermal conditions, the Kamal-Sourour model was applied with a normalization method based on the final degree of cure to enhance reliability at low temperatures.This approach yielded clearly defined Arrhenius parameters and demonstrated high fitting accuracy.For non-isothermal conditions, the Sestak-Berggren model incorporating dynamic exponential terms was adopted to capture the complex reaction mechanisms.Although this model produced high coefficients of determination and accurate Arrhenius parameters, the physical interpretation of the parameters was found to be unclear.These results suggest that the Kamal-Sourour model is well-suited for precise process control under thermally stable curing environments, while the Sestak-Berggren model, despite its numerical flexibility, requires further validation regarding its physical relevance.