Surface flashover is a critical bottleneck restricting the reliable operation of electrical equipment. Although porous structures have proven effective in enhancing flashover strength

existing construction methods are difficult to apply to traditional insulating materials like epoxy resin. We successfully prepared porous epoxy resin insulation materials through thermal curing combined with an oil-water phase separation method. Porous structure in epoxy resin is constructed by the suspended water droplets. By adjusting the water phase content (5%~40%)

we regulated the porous morphology of the epoxy matrix and analyzed the influence of pores on material hydrophobicity and flashover strength. Through potential decay analysis

potential scanning

and discharge path observation

the mechanism of porous structure in enhancing flashover strength is revealed. The results indicate that

when the pore-forming agent (water) content reaches 10%~20%

the flashover strength improvement is optimal

showing a maximum enhancement of 24.8% compared to non-porous materials. The enhancement can be attributed to the combined effects of pore-induced surface charge dissipation and corona stabilization.