Effect of UV Radiation on Liquid Silicone Rubber

SiR (Silicone rubber) composite insulators are widely used in China due to their characteristics like excellent anti-polluting-flashover performance, lighter weight, easy transportation and installation. In addition to HTV (hightemperature vulcanized silicone rubber) and RTV (roomtemperature vulcanized silicone rubber), LSR (liquid silicone rubber) material is increasingly used for high voltage external insulation in recent years. Outdoor insulators are exposed to longterm sunlight. UV (ultraviolet) radiation may cause the fracture of silicone rubber, the changes of internal structure, even oxidation and degradation reactions. Therefore, the aging characteristics of LSR under UV radiation is very noteworthy, where there is still a lack of research. In this paper, 1000h continuous aging were conducted using accelerated UV aging apparatus. The changes of static contact angle, hydrophobic transfer ability and Shore hardness during the test were measured, and fitting formulas were given. Besides, the microphysicochemical characteristics were analyzed by FTIR and XPS. Finally, UV aging results of LSR and HTV were compared.