Surface Modification,Interfacial Adhesion And Metallization Of Carbon Fiber

Carbon fiber has significant mechanical,thermal,electrical and other performance advantages.However,carbon fiber surface which is non-polarity,poor wettability,surface inertia and smooth characteristics,result in the interface problem in the composite with other matrix,which needs to be solved urgently.Inspired by the mussel viscous protein,the non-selective dopamine-bionic modification method was applied to the surface modification of materials without selective modification of the surface properties.However,the high price limits industrialization,and the main adhesion mechanisms of dopamine are catechol structure and terminal amino structure.Therefore,it is attempted to use the cheap catechol and polyethylene-polyamine as the dopamine replacement system.In this paper,continuous carbon fiber and chopped carbon fiber were biomimetic modified with catechol/polyethylene-polyamine,and secondary functionalization was used to improve interfacial adhesion and electrical conductivity.The details are as follows:(1)Through the catechol/polyethylene-polyamine biomimetic modification method,surface functionalization of continuous carbon fiber was achieved and the active groups were introduced on the surface of continuous carbon fiber.By means of SEM,EDS,XPS,TGA and other characterization methods,the optimal conditions for continuous carbon fiber surface modification with catechol/polyethylene-polyamine are:catechol-tetraethylenepentamine with pH value of 9.5,reacting 4h.The interface extraction force of the continuous carbon fiber/rubber composite increased by 21.3%.The biomimetic modification method of catechol/polyethylene-polyamine is environmentally friendly and mild.The cost is less than 1%of dopamine modification method's cost.(2)By secondary grafting of KH560,the epoxy group was introduced on the surface of continuous carbon fiber to improve the bonding performance of continuous carbon fiber and rubber.By means of XPS,FTIR,SEM,TGA,H extraction force and other characterization methods,the optimal conditions for secondary grafting of KH560 on continuous carbon fiber surface coated with poly(catechol/polyethylene-polyamine)deposits are:Applying one-step process,the grafting solution included in KH560 dosage 1.0 vol%and methanol dosage 2.5 vol ‰,which reacts at 55? and in 3 h.The interface extraction force of the continuous carbon fiber/rubber composite increased by 62.0%,which is better than that of carbon fiberdirectly grafted KH560(29.0%).The one-step process of secondary grafting KH560 is highly convenient and efficient.The application prospect of carbon fiber/rubber composites is promising.(3)Through the bionic modification of catechol/tetraethylene pentamine and the method of secondary electroless silver plating,high conductive silver-plated chopped carbon fiber was prepared.By means of XRD,XPS,SEM,TGA,four-probe conductivity and other characterization methods,the optimal conditions for co-deposition of catechol/tetraethyllene-pentamine on the surface of chopped carbon fiber with electroless silver plating are:treatment of 10 mM catechol/tetraethylenepentamine with pH value of 9.5 reacts in 2 h.The conductivity of the silver-plated chopped carbon fiber was up to 73619 S/cm after the silver-plating solution was treated for 1h.After the silver-plating solution was treated for 1h,the conductivity of the silver-plated chopped carbon fiber was up to 73619 S/cm.The conductivity of carbon fiber was significantly higher than that of carbon fiber(909 S/cm).The preparation of highly conductive silver-plated carbon fiber by catechol/polyamine modification method is highly efficient and controllable.The process is simple.The application potential in electromagnetic shielding materials is enormous.