Optimizing the cure cycle of aerospace-grade carbon fiber-reinforced epoxy composites through comparative analysis of resin and prepreg cure kinetics

Official URL: https://dx.doi.org/10.1002/pc.70067

This study optimized the cure cycle of an aerospace-grade CFRP composite by examining the cure kinetics of a DGEBA-based epoxy resin and its twill weave carbon fiber prepreg. Cure kinetics, analyzed via HP-DSC at 1, 3, 5.6, and 7 bar, showed that increased pressure significantly extended the resin's curing time but not the prepreg's. Model-Free Kinetics analysis performed was accurate for the prepreg but not for the resin. Rheological analyses showed higher initial viscosity in the prepreg, while the resin displayed a sharper rise in complex viscosity during curing. Using prepreg kinetic data, two optimized cure cycles were developed for fabrication at 3 and 7 bars. Thermal and mechanical testing of composites confirmed the effectiveness of the proposed cycles. This study emphasizes prioritizing prepreg-based cure kinetics over resin data to achieve optimal composite fabrication.