The Preparation Process And Reasearch Of Carbon Nanotubes/Carbon Fiber/Polymer Composite Materials

Carbon-fiber (CF) reinforced polyamide-6(PA6) composites and Carbon nanotubes/CFreinforced polyamide-6(PA6) composites were prepared by melt-extrusionvia continuous fiberfed during extruding. Their microstructure, mechanical properties and conductivity were studied.Three kinds of impact modifier POE, Salin8921, MN493D were added to the PA6/CF andCNT/CF/PA6composites to overcome the brittle shortcoming. The microstructure, mechanicalproperties and conductivity were also discussed. The coupling agent treatment of carbon fiberand carbon nanotube sizing agent of PA6/CF composites to overcome the carbon fiber rein-forced composite material interface bonding strength of poor shortcoming. The microstructure,mechanical properties and conductivity were also discussed. Meanwhile, studied the influenceof microstructure, mechanical properties and conductivity of PA6/CF composites withdifferent filling quantity of carbon fiber.The results showed that impact modifier MN493D showed better compatibility with PA6matrix than the others. The impact modifier MN493D showed good compatibility with PA6matrix. The PA6/Impact modifier blends owned higher enlongation at break, and their impactstrength were10times compare with that pure PA6, while their tensile strength and moduluswere decreased. With the addition of impact modifier MN493D in PA6matrix, the impactstrength of PA6/CF composites were doubled enhanced, while the reduce of tensile strengthand modulus, bending strength and modulus of PA6/CF were decreased. When the PA6/CFcomposites of carbon fiber content is10%, with the addition of impact modifier MN493D, thecomposites have better comprehensive mechanical properties. Meanwhile, the tensile strength,modulus and impact strength of PA6/CF composites were122MPa,7120MPa,10KJ/cm2.With the addition of impact modifiers MN493D, the nucleating ability and crystallinggrowing rates were decreased, and the interfacial strenghth of carbon fiber and PA6matrixwere improved.After the carbon fiber treatmented by the coupling agent, active groups were formed onthe surface of the carbon fiber and the reaction to PA6is reinforced. After the coupling agenttreatment, microstructure of PA6/CF composites changed and carbon fiber and matrixmaterial interface binding has been significantly improved. Because the interface bond strength increases, the mechanical properties of the PA6/CF composites have been greatlyimproved, compared with the PA6/CF composites without coupling agent treatment, thetensile strength increased from98MPa to123MPa, increased by25.5%; modulus is increasedfrom7216.4MPa to8344.9MPa, increased by15.6%; the impact strength increased from6.8KJ/cm2to9.7KJ/cm2, increased by42.6%.Treatment with carbon fiber sizing agent for carbon nanotubes, the strength, modulus ofcarbon nanotubes is much higher than that of carbon fiber, and carbon fiber and matrix inter-face strength has been greatly improved, from the surface structure we can know that, with thetreat ment of carbon fiber sizing agent with carbon nanot ubes, the nature of carbon fiber andthe matrix PA6has a great improve, and the distribution of fiber is more uniform. At the sametime, the mechanical properties of carbon nanotube is much higher than carbon fiber, so thetreatment with carbon fiber carbon nanotubes sizing agent, mechanical properties of PA6/CFcomposite material has improved greatly.Along with the increase of carbon fiber loading level, mechanical properties andelectrical conductivity of the PA6/CF composite materials have greatly improved. Because thecarbon fiber is enhanced, the mechanical properties and conductivity are much higher thanthat of the base material of PA6, and with the content increased, which has a great effect onthe conductivity and mechanical proper ties. The carbon fiber content increased from10%to20%, and the tensile strength increased from122MPa to146MPa, increased by19.7%;modulus is increased from8344.9MPa to13208MPa, increased by58.3%; the impact strengthincreased from10KJ/cm2to15KJ/cm2, increased by50%; the surface resistance decreasedfrom105Ωto104Ω.