Analysis of influence of thermal and voltage treatments on silicone/mica electrical insulation by FT-IR ATR

An influence of thermal and voltage treatments on properties of high-temperature electrical insulating material based on mica and silicone binder was analyzed. Tested material is intended for an operation at extremely high temperatures along with electric field stress. The main aim was to describe the high temperature and electric field influence on the material inner structure. Thermal treatment was simulated by unrepeated thermal stress of 320°C for the time of 500 hours. The material was also exposed to electric field intensities ranging from 9.6 to 15.9 kV/mm for times ranging from 7 to 280 hours. The samples were analyzed via Fourier Transform Infrared Spectroscopy, using the Attenuated Total Reflectance (FT-IR ATR) technique, and also via Microscopic Analysis. According to the measurement, accelerated thermal treatment has no significant effect on the inner structure. On the contrary, voltage treatment causes expressive degradation of the material.