Effects of precure cycle on tensile and dynamical mechanical properties of carbon/benzoxazine laminates

Four designed precure cycles were applied to carbon/benzoxazine prepregs to realize different precure degrees. The quality of laminates in quasi-isotropic stacking sequence made from these precured prepregs was evaluated by void content. The effects of precure degree on tensile and dynamical mechanical properties of the laminates have been investigated. The dynamical mechanical properties of laminates with different precure degree were found to vary little from each other, while the static tensile properties (such as strength and modulus) were in negative correlation with the precure degree and the void content. Microstructures of different laminates after fracture show that the precure procedure contributes to an increase of interfacial strength. The availability of prepregs can be determined precisely by the established relation between the precure degree of prepregs and the mechanical properties of the laminates, which is likely to be an improvement on quality/cost optimization of composite manufacturing process.