Effects Of Temperature Cycling And Humidity On Silicone Rubber Material

With wider application of composite insulators in power system,its mechanical properties and electrical performance will decline,influenced by various environmental conditions.Due to the inconvenience of sampling the insulators,artificial accelerated aging method have been put forward to simulate the nature aging condition.In this paper,using high-temperature,humidity,low-temperature and temperature cycle aging method,the mechanical properties,hydrophobic and micro-electrical properties of three kinds of silicone rubber with different curing time have been discussed.According to the mechanical performance results,temperature cycle aging had the most serious impact on the silicone rubber,however the humidity aging had the lightest effects on the silicone rubber.With the increase of aging time,the mechanical performance declined more.Under the mechanical performance comparison of three vulcanized silicone rubber,it has been found that the temperature had a great impact on overcured silicone rubber,and humidity has a great impact on undercured silicone rubber.Three kinds of vulcanized silicone rubber have the similar hydrophobic performance,the hydrophobic performance decrease with the increase of aging time.The hydrophobicity lost after being immersed in water,but the hydrophobicity recovery was found with time extending.For samples after temperature cycle aging,the hydrophobicity recovery was hardly achieved,while the samples under aging condition,the hydrophobicity recovery was nearly perfect.According to the TSC test results,the current peak increased with time extending,the trap charge and trap level of silicone rubber increased with time extending.The trap level of overcured silicone rubber increased the most in the temperature aging method,and the trap level of undervcured silicone rubber increased the most in humidity aging method.The results showed that,the mechanical properties,hydrophobic and micro-electrical properties of three silicone rubber declined after aging.The aging of silicone rubber is the most serious under temperature cycle aging,in some environment conditions,the overcured silicone rubber and the undercured silicone rubber showed the defects in performance.During the curing process,the silicone will have a perfect performance under a perfect curing time.