Construction Of Gradient Interface Layer With Graphene In Carbon Fiber/bismaleimide Composites

Carbon fiber composite has been widely used in aeronautical,military industry,sports equipment and other fields due to its high strength,high modulus,low density and stable dimension.Good interfacial properties are essential to ensure the efficient load transfer from matrix to fibers,which help improve the mechanical properties.Hence,it is necessary to optimize and design the interface to enhance the fiber-matrix adhesion.In this paper,the gradient interface layer was constructed to enhance the interfacial properties of carbon fiber/bismaleimide(BMI)composites.During the construction process,the chemical and physical methods were employed to introduce graphene oxide(GO)or functional grapheme oxide(f-GO)into the interface layer of composites.FT-IR,XPS,AFM,SEM,contact angle measurement and interlaminar shear strength(ILSS)were used to characterize the structure and properties of composites.The results indicated that the f-GO was grafted onto the surface of carbon fiber successfully by chemical grafting method.The surface energy of grafted carbon fiber increased by 65.0% compared with the carbo n fiber,and the ILSS of grafted carbon fiber/BMI composite increased by 25.2%.In order to construct gradient interface layer via adsorption method,the GO or MAH-GO were absorbed on the surface of carbon fiber by immersing the carbon fiber into GO or MAH-GO resin or aqueous solutions respectively.When GO content was 0.05wt% in the resin solution and in the aqueous solution,the ILSS of composites increased by 30.9% and 9.7%,respectively,and when MAH-GO content was 0.2wt% in the resin solution,the ILSS of composites increased by 12.4%.