Nano-material Graft Modified Carbon Fiber And Its Interface Activation Design

The mechanical properties of CFRP composites were highly depended on the properties of fiber,resin Matrix and the interfacial phase between fiber and resin matrix.Design and optimization of interface could greatly improve the performance.However,the inherent property of smooth surface and chemical inertness of carbon fiber usually leaded to poor matrix compatibility and interfacial bonding.Based on above problems,the interface of the composite was designed and optimized by chemical grafting chitosan and in situ growth with,polyglycerol and carbon nanotubes as modifiers.The role of interfacial phase in composites was discussed to solve the problem of poor interfacial performance of carbon fiber reinforced resin composite and to improve the overall performance of carbon fiber reinforced resin composite.Cathodic treatment and silica in situ growth changed the surface morphology of carbon fibers and improved the monofilament tensile properties.SEM,FT-IR and Raman spectroscopy,epoxy resin adsorption experiment and electronic universal testing machine were used to research the surface morphology,chemical composition changes,wetting properties and mechanical properties of carbon fiber and its composites,respectively.The introduction of active substances on the carbon fiber surface could improve the surface area and roughness of the carbon fiber,improve the surface activity and wetting performance of the carbon fiber,so as to enhance the mechanical engagement and friction between the carbon fiber and the epoxy resin matrix,and form a transition layer that could transfer and eliminate stress.Chemical graft chitosan could make up for the damage of carbon fiber body strength caused by pretreatment.When grafting time was 24h,the performance of carbon fiber composites was optimized,interlaminar shear strength increases by 21.21%.In situ growth of polyglycerin could improve the performance of carbon fiber composites better than that of chemical graft polyglycerin,and the introduction of carbon nanotubes would further improve the performance.This was mainly attributed to the following aspects:first,the reaction point of chemically grafted HPG was affected by the structure and molecular volume,and adjacent HPG molecules were likely to affect each other;in addition,monomer was used for in situ growth,and monomer viscosity was low,and it was easier to combine with carbon fiber active sites.Cathode treatment of carbon fiber could remove epoxy slurry and improve the monofilament tensile strength of carbon fiber.Silica grown on the surface of carbon fiber in situ could make up for the damage to the performance of the carbon fiber caused by pretreatment.