The effect of rolling process on the mechanical and electrical properties of CNTs-enhanced GFRP

In this paper, the mechanical properties of glass fiber reinforced plastic (GFRP) laminates are enhanced by improving the preparation process and toughening with the nano-fillers. The carbon nanotubes (CNTs) solution was prepared and sprayed into GFRP laminates as an interlaminar enhancement layer. To explore the effect of different rolling reduction rates (1.5%, 3%, 6%) and different rolling patterns (cold rolling and hot rolling) on CNTs-enhanced GFRP, the three-point bending test, the end-notch flexure (ENF) test, and the tensile test were designed and carried out. Results revealed that the optimal rolling reduction rate was 3%, and the mechanical properties of GFRP laminates enhanced by the hot rolling process were found to be relatively superior to the cold rolling process. Simultaneously, the CNTs interlayer could significantly improve the mechanical properties of GFRP, i.e., flexural strength, mode II interlaminar fracture toughness and tensile strength enhancing with 69%, 56% and 50%, respectively. The results of the Scanning Electron Microscope (SEM) exhibited that the hot rolling pressure could accelerate the mutual diffusion of the resin and CNTs, effectively forming a fiber/resin/CNTs strengthening interface. In addition, the rolling process could cause the partial disconnection of conductive network paths of CNTs film, resulting in an increase of the resistance change rate.