A Comparative Study on Temperature Resistance of High Temperature Vulcanized Silicone Rubber and Liquid Silicone Rubber

High temperature vulcanized silicone rubber (HTVSR) insulators and Liquid silicone rubber (LSR) insulators have been widely used in transmission systems for more than 60 years. The temperature resistance is important for silicone rubber insulators. However, the comparative study of temperature resistance between HTVSR and LSR is rather lacking. Glass transition temperature (T
_g
), crystallization temperature (T
_c
), isothermal crystallization process, and thermal stability of HTVSR and LSR were compared by dynamic mechanical thermal analysis (DMA), differential scanning calorimeter (DSC), and thermogravimetric analysis (TGA). It was found that LSR is more suitable to use in low temperature regions due to its lower Tc compared with HTVSR. Besides, the isothermal crystallization kinetics of LSR has been described by the Avrami equation. LSR was found to be likely to produce truncated spherical crystals. For thermal stability, oxygen promotes the decomposition of LSR but influences the decomposition of HTV a little. However, the thermal stability of LSR is still more excellent than that of HTV. Finally, the conclusion can be drawn that LSR is more excellent than HTV in temperature resistance. LSR insulators can be applied in some cold regions and areas with large temperature changes.