Enhancing interlaminar fracture toughness of carbon fiber composite with interleaved polyvinylidene fluoride electrospun fiber veils cooperating FeOOH nanoparticles

For effectively enhancing the interlaminar fracture toughness of carbon fiber epoxy resin composite laminates (CF/EP), a modification method of nanofiber veils intercalation cooperating nanoparticles was proposed. First, the needle-like FeOOH nanoparticles were uniformly loaded on the surface of the carbon fiber cloth by spraying method, and then the prepared electrospun polyvinylidene fluoride (PVDF) nanofiber veils was interleaved between the layers of the FeOOH loaded carbon fiber cloth, and the modified composite laminate PVDF&FeOOH-CF/EP was prepared by manual laying-vacuum hot pressing method, and the effective effect and mechanism of FeOOH with different areal densities in enhancing the interlaminar fracture toughness of CF/EP with the PVDF were studied. The results show that FeOOH is evenly distributed on the carbon fiber cloth. When the areal density is 2 g/m², the PVDF&FeOOH-CF/EP laminate has the best toughening effect. Compared with that of CF/EP, the mode-I interlaminar fracture toughness G_IC is increased by 118% and mode-II interlaminar fracture toughness G_IIC is increased by 97%, while the G_IC and G_IIC of PVDF-CF/EP only are increased by 70% and 44%, respectively. SEM analysis shows that the addition of FeOOH not only improves the fracture toughness of the matrix, but also enhances the interface between the PVDF fiber and the matrix epoxy resin, thereby enhancing the toughening behavior of PVDF fiber.