In order to improve the surface characteristics of high-voltage composite bushings

two commercial liquid silicone rubbers are fluorinated using F

2

/N

2

mixed gas. The electrical properties

physical and chemical properties

and hydrophobicity of the two liquid silicone rubber samples before and after fluorination are tested. The results shows that the DC flashover voltages of the two silicone rubber samples after fluorination have increased by more than 50% and 30% respectively. The two silicone rubber samples present different surface potential decay characteristics after fluorination. The surface conductivity of both is increased by 1~2 orders of magnitude

and the

bulk conductivity does not change significantly. The increase in surface conduction caused by fluorination can accelerate the surface potential decay. Through ATR-IR analysis and SEM observation

C—F bonds are formed in the surface layer of the fluorinated samples

and micro-nano structuring appears on the surface of the fluorinated layer. The hydrophobicity test indicats that fluorination significantly has improved the hydrophobicity of the two liquid silicone rubber samples. Therefore

fluorination treatment is an effective means to enhance the surface performance of liquid silicone rubber used in high-voltage composite bushings.