Effects Of γ-RAY Irradiation On Indigenous Aramid Fiber And Its Composite Interface Performance

In recent years, aramid fiber is widely used because it's excellent performance. However, the aramid fiber surface is so inert that the interface properties of composite materials are unsatisfied. Aramid is researched in our country late, although the indigenous aramid fiber already has high strength and high modulus, its surface is so smooth, and the wetting property with resin is so poor. In this paper, 60Coγ-ray irradiation graft technology is used to improve the interface properties of the indigenous aramid fiber reinforced epoxy composite.The scanning electron microscopy (SEM) and atom forced microscopy (AFM) are used to research the surface appearance of aramid fiber, as the result, the surface of fiber have a lot of raised bubble afterγ-ray irradiation. The fiber surface roughness is increased. With the increase of the radiation dose, the number of convex is increased. As the radiation dose go to 400kGy, it is reached the maximum, and then decrease. It is good for improving the interface properties of composite. The surface chemical elements and functional groups of untreated and irradiated Aramid fiber are observed by photoelectron spectroscopy (XPS). As the result, the number of polar groups is increased afterγ-ray irradiation. This will enhance the wetting property between Aramid fiber and Epoxy resin. The contact angles between Aramid fiber and Epoxy resin is texted to compute the fiber surface energy. The results show that the contact angles decreased after theγ-ray irradiation and the fiber surface energy improved.The tensile strength of single fiber is tested, and the two-parameter Weibull distribution method is used to compute statistical average strength. The results indicate that the effect ofγ-ray irradiation on the strength of Aramid fiber body is not obvious, and it is acceptable. The interfacial properties of single Aramid fiber reinforced epoxy composite (IFSS) are tested. The results show that the properties are improved. The interlayer shear strength (ILSS) and flexural strength are texted. The results show that the optimum irradiation condition is epoxy chloropropane used as grafting solution under the irradiation dose of 400kGy.