Effects of 6FAP on the Electrical Properties of Al₂O₃/Epoxy Resin Composites

Abstract

The fluorination of Al2O3/epoxy composites is achieved through the grafting of 2,2‐bis(3‐amino‐4‐hydroxyphenyl) hexafluoro propane (6FAP) onto the epoxy molecule via ring‐opening reactions. The microstructures, Fourier infrared spectra, and water contact angle of the untreated and fluorinated Al2O3/epoxy composites are characterized. The composites' dielectric properties and DC conductivity, DC breakdown, surface flashover, and surface potential decay are also measured. The results demonstrate that 6FAP has been successfully grafted onto the epoxy molecules, and Al2O3 particles are uniformly distributed in the composite. The hydrophilicity of the fluorinated Al2O3/epoxy composite is enhanced. The fluorinated Al2O3/epoxy composite exhibits more favorable electrical properties than the untreated composite. The breakdown strength and surface flashover voltage of the fluorinated Al2O3/epoxy composite increased by 12.98% and 11.10%, respectively. Compared to the untreated composite, the deep trap density of the fluorinated Al2O3/epoxy composite increases, which contributes to the reduction in carrier mobility and to the enhancement of breakdown strength and surface flashover voltage. This work suggests that fluorination via 6FAP has potential applications in the improvement of electrically insulating materials.