Research On Modified Carbon Fiber Based On Dopamine Self-polymerization And Mechanical Properties Of Carbon Fiber Composites

Carbon fiber reinforced resin-based composite materials are widely used in aircraft,spacecraft and other spacecraft components due to their excellent mechanical properties and light weight,but the carbon fiber surface is smoothly and chemically inert,and the surface energy is low,when combined with matrix resin,the interfacial wetting and bonding properties of the composites will be very poor,which makes it difficult to full use of excellent performance of carbon fiber.Therefore,the carbon fiber is surface-treated before use to increase the specific surface area and surface activity of the carbon fiber,and to improve its adhesion to the resin.Based on the bionic principle of natural mussels,polydopamine is coated on the surface of carbon fiber by dopamine self-polymerization-adhesion behavior,then to explore the influence of dopamine on the modification of carbon fiber.Combined with the results of scanning,infrared and other testing methods,3 h and 6 h were selected as the next experimental conditions.Next,copolymerization of dopamine and amine-functionalized carbon nanotubes(CNTs-NH2)on the fiber surface at room temperature,carbon nanotubes and carbon fibers have similar structures and compositions.Then,we prepared CF-PDA-CNTs reinforced composites.The surface morphology and chemical composition of the modified carbon fiber were tested by infrared spectrum(FT-IR),scanning electron microscope(SEM),atomic force microscope(AFM).The mechanical properties of the resulting composites were characterized by dynamic thermal analyzer(DMA)and universal testing machine.The results showed that there were a large number of carbon nanotubes on the surface of carbon fiber when the content of amine-functionalized carbon nanotubes was 0.05 g for 6 h.The best modification effect on carbon fiber improved the mechanical properties of resulting composites.This indicates that PDA and CNTs on the surface of carbon fiber not only introduced reactive functional groups,but also increased the surface roughness of the fiber,thereby improving the mechanical properties of the carbon fiber/epoxy composite.The research work of this thesis provides a new idea for the introduction and regulation of carbon nanotubes on the surface of carbon fiber,and provides a new feasible solution for the preparation of high performance resin-based composites.