Enhance the Surface Insulation Properties of EP Materials via Plasma and Fluorine-Containing Coupling Agent Co-Fluorinated Graphene

Epoxy resin (EP) is an outstanding polymer material known for its low cost, ease of preparation, excellent electrical insulation properties, mechanical strength, and chemical stability. It is widely used in high- and ultra-high-voltage power transmission and transformation equipment. However, as voltage levels continue to increase, EP materials are gradually failing to meet the performance demands of operational environments. Thus, the development of high-performance epoxy resin materials has become crucial. In this study, a combined treatment using plasma and a fluorine-containing coupling agent was employed to fluorinate graphene nanosheets (GNSs), resulting in DFGNSs. Different concentrations of GNSs/DFGNS-modified EP composites were prepared, and their effects on enhancing the surface insulation properties were studied. Tests on surface flashover voltage, surface charge dissipation, trap distribution, and surface resistivity demonstrated that both GNSs and DFGNSs significantly improve the insulation properties of EP materials. Optimal improvement was achieved with a DFGNS content of 0.2 wt%, where the flashover voltage increased by 16.23%.