Curing kinetics and mechanical properties of the epoxy vitrimer based on transesterification and its composite laminates

The resin is a fundamental factor in determining the performance and usage conditions of its composites. The epoxy vitrimer, which combines both thermoplastic and thermosetting properties, shows significant potential in extending the service life of material. The curing process significantly affects the macroscopic properties of the vitrimer and the resulting carbon fiber reinforced plastics (CFRP). Effective control of curing parameters constitutes the critical factor for the assurance of product quality. In the study, a differential scanning calorimetry (DSC) was utilized to establish a curing kinetics model for a modified, self-healable epoxy vitrimer based on transesterification. Then the molecular structure, thermodynamic, and mechanical properties of the cured vitrimer were analyzed. Next vitrimeric CFRP (vCFRP) laminates were fabricated, and the tensile and bending properties of the vCFRP laminates were investigated. The results showed the curing process was obtained: 95 degrees C/1 h + 150 degrees C/2 h + 170 degrees C/2 h. The thermodynamic and mechanical properties of cured vitrimer could meet practical requirements. The minimal differences observed in the stress-strain curves of the specimens indicated that the curing process was appropriately configured. The prepared laminates exhibited performance comparable to that of commercial thermosetting composites. Schematic images of research on curing kinetics and performance for epoxy vitrimer and its composites based on transesterification. image