Effect of Electric Field on Water Absorption and Permeability Characteristics of Silicone Rubber

Moisture intrusion into the silicone rubber (SR) sheath may trigger composite insulator failure, so it is especially crucial to study the water absorption and permeability characteristics of SR under different conditions to prevent and control the failure; however, there are few studies on the influence of electric field. In this work, the effect of electric field on the water absorption and permeability characteristics of SR is reported. The results show that the electric field has an inhibitory effect on the water absorption of SR, and the diffusion coefficient and the percentage of saturated water absorption decrease by 34.4% and 82.6%, respectively, with the increase of the electric field intensity. Meanwhile, the permeability characteristics of moisture through SR are studied, and it is found that the permeation rate increases with the increase of forward voltage, while the reverse voltage is the opposite. Finally, molecular simulation is utilized to calculate the diffusion coefficient, free volume, and intermolecular interaction energy of the SR system containing water under the effect of different electric fields, which further verifies the accuracy of the experimental results. By this study, the variation rules of water absorption and permeability of SR under the effect of electric field are supplemented.