Nano-enhancement Effect Of BGE-GO On The Interface Of T800/Epoxy Composites

Carbon fiber resin-based composite materials have excellent properties such as low density,high modulus and high tensile strength,and are widely used in transportation,aerospace,wind power and sporting goods.The interfacial phase between the carbon fiber and the resin matrix is a special component of the composite,which determines the structural-functional properties of the composite to some extent.Therefore,improving the interfacial bonding of composite materials has become one of the key scientific issues in the preparation of high performance composite materials.Based on the design idea of "nano-enhanced lock-enhanced interface phase",n-butyl glycidyl ether(BGE)modified graphene oxide(BGE-GO)was prepared by chemical grafting method.It is also introduced into the surface of T800 carbon fiber and epoxy resin matrix.The influence of BGE-GO on the interfacial properties of T800 carbon fiber/epoxy composite is systematically studied,and the theoretical basis and basic data for the preparation of composites with high interfacial bonding strength are provided.KH550-GO was prepared by grafting KH550 onto the surface of GO based on chemical grafting,and BGE was grafted on the surface of KH550-GO to prepare BGE-GO.FTIR,XPS,TGA and other means showed that BGE was successfully grafted onto GO.BGE-GO modified carbon fiber(BGE-GO@CF)was successfully prepared based on physical coating method and solvothermal method,respectively.The results of scanning electron microscopy(SEM)and atomic force microscopy(AFM)showed that BGE-GO was successfully introduced onto the surface of carbon fiber and dispersed evenly on the surface of carbon fiber.Compared with the physical coating method,more BGE-GO is introduced into the carbon fiber in a solvothermal method.Optical microscopy showed that GO agglomerated in the resin matrix,and BGE-GO was well dispersed in the resin matrix,which proved that the surface organic modified layer of BGE greatly improved the chemical compatibility and dispersion of BGE-GO in the resin matrix.The effect of BGE-GO on the nano-strengthening effect of T800 carbon fiber/epoxy composites was systematically studied.The results of transverse fiber bundle test(TFBT)and tow pull-out test(FBPT)show that BGE-GO can significantly improve the tensile strength of TFBT composites and the interfacial shear strength of FBPT composites.When the content of BGE-GO is 1.5 wt.%,BGE-GO@CF/BGE-GO@EP composite exhibits the best interfacial properties.For BGE-GO@CF prepared by physical coating method,the tensile strength of the TFBT specimens and the interfacial shear strength of the FBPT specimens of the BGE-GO@CF/BGE-GO@EP composite were increased by 61.1%and 48.0%,respectively.For BGE-GO@CF prepared by solvothermal method,the tensile strength of the TFBT specimens and the interfacial shear strength of the FBPT specimens of the BGE-GO@CF/BGE-GO@EP composite were increased by 72.2%and 82.0%,respectively.The resistance change of the composite during the testing process was characterized by the electric resistance method.The test results show that the ratio of the resistance change value of the BGE-GO@CF/BGE-GO@EP composite material to the initial resistance(AR/RO)is the smallest,which proves the composite interface has the best bonding performance,and the conclusion is basically consistent with the conclusions of the TFBT specimens and the FBPT specimens.The interface morphology and modulus of the composites were characterized by AFM image and interface modulus analysis.The test results show that BGE-GO can increase the thickness of the transition layer of the composite interface and facilitate the transfer of stress from carbon fiber to resin matrix.Thereby effectively improving the interface properties of the composite material.