Influence of single and multiple environmental stresses on tracking and erosion of RTV silicone rubber

Single and multiple effects of UV, corona, thermal, water absorption and acid rain stresses on the tracking and erosion characteristics of room temperature vulcanized silicone rubber (RTV) are investigated. It is shown that corona stress and water absorption stress decrease the tracking and erosion resistance of RTV, while thermal stress and UV stress improve it. Synthetic acid rain, 500× stronger than actual rain in Japan, cannot induce the change in the tracking and erosion characteristics. RTV subjected to simultaneous multiple stresses also is evaluated. Significant variations in the tracking and erosion resistance appear. Chemical and morphological analysis for assessing the aging level is carried out by scanning electron microscope (SEM)-energy dispersive X-ray (EDX), attenuated total reflection (ATR)-Fourier transform infrared (FTIR) and differential scanning calorimetry (DSC). In this study, DSC plays an important role to detect boiling and combustion temperatures of byproducts affecting tracking and erosion. Noteworthy results are obtained in that the decrease in the resistance to tracking and erosion is related to the formation of byproducts that burn at low temperature (170 to 275°C)