Effect of toughened polyamide/carbon fiber interlace braid fabric on the mechanical performance of CFRP laminates

Delamination resistance and epoxy matrix brittle fracture have been the main issues in carbon/epoxy composites laminates. Various studies have been reported to complement the brittle fracture of epoxy matrix. Conventional methods of fabricating toughened carbon/epoxy composite laminates were thermo-plastic veils and films interleaving methods, directly toughening the matrix resin and dispersing nanoparticles in the matrix. In this study, the carbon/epoxy composites laminates were manufactured using carbon fiber/polyamide fiber braided fabrics. The chemical interactions between polyamide and epoxy matrix resin were investigated by Fourier transform infrared spectroscopy, which resulted in ring opening of the epoxide group by the amide group. The compression after impact strength and the interlaminar toughness of the carbon/epoxy composite laminate were increased by 31%, and the strain energy release rates were increased by 120% compared to the virgin interface composite. In the case of carbon/epoxy composite laminates interlaced with polyamide fibers, the mechanical properties, such as the tensile strength and fatigue properties, were improved as tensile modulus decreased.