Effect of UV Irradiation on the Surface Morphology and Chemical Structure of Epoxy Resin

Ultraviolet (UV) irradiation is an environmentally friendly method for material modification. In order to explore the effect of UV irradiation on surface properties of epoxy resin and further explore the feasibility of this method on improving surface flashover of epoxy resin, in this paper we experimentally study the surface morphology and chemical structure of epoxy resin after UV irradiation. It was shown that after irradiation, the surface morphologies and roughness of the samples shown little change. The FTIR results showed that after UV irradiation, the O-H and C=O groups on the surface were increased, while the content of CH2 and CH3 groups was decreased greatly. We further studied the surface chemical components by XPS and it was revealed that the C-C/C-H and C-O-C bonds on the surface decreased significantly by UV irradiation, and the C-O-H and C=O bonds increased significantly. Through molecular simulation calculations, it was found that the bond energies of C-O-C, C-H, and C-C bonds in epoxy molecules are low, and thus they were prone to fracture by UV irradiation. This study elucidated the mechanism of UV irradiation on changing the surface chemical structure of epoxy resin, and provided a basis for improving the surface flashover performance of epoxy resin by UV irradiation.