Fabrication and strengthen mechanisms of aligned carbon nanotube sheet/cyano resin composites

The CNT sheet prepregs were fabricated by cyano resin solution impregnating continuous carbon nanotube (CNT) sheet, which was prepared by floating catalyst chemical vapor deposition grown (FCCVD) method. A well aligned CNT sheet composite was fabricated by subsequent hot-stretching treatment and hot pressing process. The effects of hot-stretching temperature and resin solution concentration on the tensile properties of the CNT prepregs were analyzed and the hot-stretching process was optimized. The effect of curing cycle on the tensile properties of CNT sheet reinforced cyano resin matrix composite was studied. Through analyzing the wetting characteristics, CNT alignment and interlaminar shear strength, the strengthen mechanisms of CNT sheet reinforced cyano resin matrix composites were revealed. The results indicate that the CNT sheet prepreg hot stretching process is more beneficial for getting highly aligned CNTs within the CNT sheet reinforced cyano resin matrix composite than the traditional CNT sheet stretching process. The temperature and resin solution concentration are the key factors to prepare high property cyano resin impregnated CNT film, which has high CNT orientation and low porosity. Through changing the curing cycle, the extent of reaction of cyano resin and the tensile properties of the CNT sheet/cyano resin composite are improved. The tensile strength and modulus of the CNT sheet/cyano resin composite reach up to 2 748 MPa and 302 GPa after postprocessing. Benefited from the superior wetting property, the high interlaminar shear strength and the high alignment degree of CNTs, the CNT sheet/cyano resin composite shows high tensile properties, due to efficient load bearing inside the CNT network.