To further explore the long-term influence of voltage stabilizers on silicone rubber (SiR), the electrical properties of unmodified SiR and SiR modified by two types of voltage stabilizers with high electron affinity were investigated after thermal aging. In this paper, three different kinds of SiR were thermally aged for 0, 40, and 80 days at 120℃. Then the characterization and electrical properties measurements were carried out. The results showed that the breakdown strength of SiR modified by voltage stabilizers after aging was still significantly higher than that of the unmodified SiR and that the conductivity of modified SiR reduced slightly at all aging stages. In addition, the space charge characteristics of the modified SiR also improved after aging. There were two main reasons. First, the cross-linked degree of SiR increased during the aging process. Second, the voltage stabilizers with high electron affinity migrated during the aging process and slowed down the thermal aging process of the SiR.

Voltage Stabilizers, Thermal Aging, Silicone Rubber, Breakdown, Space Charge