Review on Degradation Behaviors of Silicone Rubber Under Ultraviolet Radiation for Outdoor Insulators

Silicone rubber composite insulators are widely used in high-altitude areas. The strong ultraviolet radiation in high-altitude areas can induce the photooxidation reaction of silicone rubber materials, degrade the service characteristics of silicone rubber materials, and seriously threaten the reliability of composite insulators. Many researchers have used various methods such as UV-A, UV-B, UV-C, xenon lamps, etc. to simulate ultraviolet radiation in high-altitude areas and artificially accelerate the aging of silicone rubber materials. Besides, extensive researches on the evolution behavior of the microstructure and macroscopic properties of silicone rubber materials under ultraviolet irradiation have also been conducted. However, gradient damage characteristics caused by UV aging in silicone rubber have not yet been studied. In addition, the used methods in previous reports cannot accurately detect uneven molecular structure information of silicone rubber under UV irradiation. Furthermore, the inherent relationship between the uneven aging state and key performance is still needed to investigated. Therefore, it is necessary to study the multi-scale non-uniformity of silicone rubber materials under UV irradiation and construct its inherent correlation with key performance in future researches, which can provide the theoretical foundation for the reliable operation of composite insulators in high-altitude areas.