Interlaminar performance of 3D CNTs/carbon black film enhanced GFRP under low-temperature cycling

Abstract

Unidirectional Glass Fiber Reinforced Plastic (GFRP) laminates were prepared by inserting three-dimensional (3D) CNTs/carbon black film or CNTs/graphene oxide (GO) film into the laminates to improve the interlaminar performance. The effects of low-temperature cycles (35 cycles between −58 °C and room temperature (RT)) on the samples were investigated, and the damage caused to the reinforcement layer was directly detected by comparing the interlaminar images. By comparing the experimental results of the double cantilever beam (DCB) and end notch bending (ENF) test, the optimising effect of the new composite film (CNTs/carbon black film) on the interlaminar fracture toughness was verified. The results showed that the interlaminar fracture toughness of CNTs/GO film and CNTs/carbon black film in modes I (ENF test) and II (DCB test) was similar and superior to that of CNTs film. Regarding the effect of the low-temperature cycles on the samples, the change of CNTs/carbon black film and CNTs/GO film is also lower than that of CNTs film. Finally, the matrix interface and failure mechanisms of the interlaminar reinforcement were investigated by scanning electron microscope (SEM).