Thermal Degradation of Fatigue Strength and Viscoelastic Behavior of Chlorosulfonated Polyethylene Rubber
Tomohiro NARUSE, Toshio HATTORI, Yukihiro YAMAGUCHI,Tetsuya KANAI and Takashi SEKIYA
Abstract:Chlorosulfonated polyethylene rubber(CSM) is used in tubes and wire covers among many other uses. Generally, rubber shows considerable changes in mechanical properties over time and in temperature. To confirm the reliability of these products, we must evaluate how they degrade in humidity, sunlight, and under thermal loading. We therefore studied the thermally degrading properties of CSM. We first measured thermal reduction of the elongation and of the fatigue strength of CSM. To evaluate these degrading properties, we used the Arrhenius's equation to confirm the relationship between the temperature and the time. Using these evaluation methods we can predict thermal reduction of fatigue strength taking temperature and exposure time into account. The time-temperature shift factor of thermal degradation of the elongation agrees well with that of the fatigue strength. Viscoelastic behavior of virgin CSM and that of thermally degraded one were evaluated. Arrheniusfs equation was found to describe the temperature dependence of thermal degradation of complex modulus. The time-temperature shift factor of thermal degradation of a complex modulus does not agree with that of elongation and fatigue strength. Key Words:Rubber, Fatigue strength, Viscoelastic behavior, Thermal degradation