Modification of rayon based carbon fiber surface by ⁶⁰Co_γ-ray irradiation inducing grafting

⁶⁰Co_γ-ray irradiation inducing grafting was used to modify the rayon based carbon fiber surface to improve the interfacial adhesion between fibers and the matrix to study the effect of different solutions and absorption doses on grafting yields and interfacial properties of fiber reinforced epoxy composites and the effect of absorption doses on the tensile strength of carbon fibers. The observations of morphological changes in the fiber surface and the fracture surface of composites after irradiation inducing grafting using scanning electrical microscopy (SEM) indicated that 3% epoxy/acetone solution system is an optimal solution for the modification of carbon fiber by irradiation inducing grafting; the grafting yield on the fibers surface is 4.2% after irradiation in this solution at an absorption dose of more than 0.1 kGy; the interlaminar shear strength (ILSS) of the composite is increased by more than 20%; the radiation may increase the tensile strength of carbon fibers at an appropriate absorption dose; and the obviously increased roughness of fiber surface after grafting enhances the interfacial mechanical engagement between fibers and the matrix.