宇航级 T800 碳纤维复合材料界面调控

The effect of the sizing agent on the surface modification of high-performance carbon fiber (CF) and the modulation effect on the interface performance of its composite is very important. In this paper, the aerospace-grade T800 carbon fibers prepared by the wet method are used, and the changes in the surface microstructure, chemical composition, and chemical reaction characteristics of the fiber before and after sizing are analyzed, and the macro and micro interface properties of the composites are characterized. In addition, the reactivity of the sizing agent and its chemical reaction behavior with epoxy resin (EP) and bismaleimide resin (BMI) were examined using X-ray photoelectron spectroscopy (XPS), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), and other characterization techniques. The results show that the sizing agent reacts chemically with the groups on the fiber surface under the curing temperature of the resin so that the extraction amount of the sizing agent and the content of active carbon atoms on the fiber surface is reduced. The sizing agent has good chemical reaction characteristics with EP and BMI. The surface of CF sizing agent is rendered inactive after the high-temperature treatment, which also results in a little change in the interface shear strength between CF and EP but a 13% reduction between CF and BMI. In conclusion, the epoxy sizing agent with chemical activity can significantly improve the surface properties of carbon fiber, and then affect the interface properties of composites, in which the reactivity between the sizing agent and resin also affects the interface performance.