New Surface Activation Method Of Carbon Fiber

Carbon fiber and its composite material is a new type of material which has grown up with the development of military industry,and it belongs to the high and new technology products,with high specific strength,high specific modulus,high temperature resistance, corrosion resistance, fatigue resistance, creep resistance, conductive, heat transfer,thermal expansion coefficient and other series of excellent properties.It can as a structural material bearing load,but also play a role as a function of the material.In recent years,it’s developed rapidly. It has been widely used in many fields,such as aviation, aerospace, automotive, transportation, construction, electronics, environmental engineering,chemical,energy and so on.However,due to the interface between carbon fiber and resin matrix is combined with poor performance,so it is necessary to modify the surface of carbon fiber to improve the interfacial adhesion properties.First of all from the point of view of the physical structure,by configuring different concentrations of nitric acid,the effects of different concentrations of oxidant on the surface activation of carbon fibers were discussed.Secondly,treatment of carbon fiber surface by ultrasonic oscillation,the effects of ultrasonic vibration treatment on the surface modification of carbon fibers were discussed.Finally,starting from the point of view of chemical structure,without destroying the original crystalline structure of carbon fiber based,by azobisisobutyronitrile initiated polymerization of methacrylic acid,the effect of polymerization on the surface activation of carbon fibers were discussed.By X ray diffraction(XRD),Raman spectroscopy(Raman),infrared spectroscopy(IR),surface energy spectrum(EDS) and other characterization results to assess the effect of carbon fiber surface activation is good or bad. The results showed as following:1.After nitric acid oxidation, carbon fiber surface roughness increased.With the increase of the concentration of nitric acid, surface oxygen content increased too.2.Ultrasonic vibration can not only increase the number of surface functional groups of the activated fiber, it can also increase the spacing between the surface grain and grain(thus for the following polymerization introducing active monomers were prepared).3.After the polymerization process,the surface growth of methacrylic acid.Due to the introduction of hydroxyl, carbonyl, carboxyl and other functional groups,the increase in the number of surface active functional groups,to improve the effect of fiber surface activation.And with the increase of polymerization time,the activation effect is more significant.