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Silicone rubber is the highest level of heat resistance of all rubber, silicone rubber in the air heat aging, cross-linking occurs, the degree of reduction in the elongation of its torn than the degree of reduction in tensile strength is much larger. Silicone rubber has excellent resistance to dry heat and air aging, but does not resist moisture aging. When there is excessive moisture in the air or in the specimen, the vulcanized rubber will undergo strong degradation. Silicone rubber aging at 315°C for 24h, the strength of the vulcanized rubber is basically unchanged, but when the humidity is 180g/m2, the specimen is damaged. In addition, silicone rubber will also be strongly degraded under the closed aging conditions with no air circulation, which will deteriorate the performance. Silicone rubber heat resistance depends mainly on its molecular structure: methyl vinyl silicone rubber and methyl phenyl vinyl silicone rubber, long-term use of the maximum temperature of 250 ° C; and ethyl silicone rubber, long-term use of the maximum temperature does not exceed 200 ° C. With the increase in the phenyl content of the silicone rubber, heat resistance. For example, phenylidene silicone rubber, phenylidene ether silicone rubber high temperature resistance of 300 ° C or more. In the silicone rubber In the silicone rubber, boron silicone rubber has the best heat resistance. This kind of silicone rubber can work for a long time at 400 ° C, in 420 ° C to 480 ° C can work continuously for a few hours.
