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

ABSTRACT The fluorination of Al 2 O 3 /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 Al 2 O 3 /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 Al 2 O 3 particles are uniformly distributed in the composite. The hydrophilicity of the fluorinated Al 2 O 3 /epoxy composite is enhanced. The fluorinated Al 2 O 3 /epoxy composite exhibits more favorable electrical properties than the untreated composite. The breakdown strength and surface flashover voltage of the fluorinated Al 2 O 3 /epoxy composite increased by 12.98% and 11.10%, respectively. Compared to the untreated composite, the deep trap density of the fluorinated Al 2 O 3 /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.