Investigation of High-Temperature Stability and Thermal Endurance of Silicone Potting Compound by Thermo-Gravimetric Analysis

The high-temperature stability and thermal life of silicone resin-based potting compound (SC-3), used in the aerospace application for electrical insulation, is investigated Thermo-Gravimetry Analysis (TGA) in an inert environment. Nonisothermal TGA is performed in the temperature range of 30 °C to 900 °C at 10, 20, and 30 °C / min heating rates. The kinetic parameters such as activation energy and pre-exponential factor are obtained by the model-free method proposed by Kissinger-Akahira-Sunose (KAS) and Flynn Wall Ozawa (FWO) at various degree of conversion. The thermal degradation of the SC-3 compound is observed in the temperature range of 350 °C to 580 °C, and thermal endurance or time of failure of potting compound SC-3 is estimated as per ASTM E1877 standard. The results reveal that the potting compound SC-3 can be safely used continuously at 100 °C and for ~3.6 min at 350 °C. Experimental results are also useful to understand the degradation mechanism of the SC-3 compound.