Performance Evaluation of Nano MgO Filled Polymer Material for High Voltage Insulation

Silicone rubber insulators has been used in outdoor insulation, under environmental and electrical stress, its long term performance gets affected. Its service life span can be improved by addition of inorganic nano fillers. In this work magnesium oxide nano fillers have been synthesized in the laboratory, its particle size is in nano range is ascertained with XRDE. The silicone rubber flat plate specimens are prepared with 0, 1, 3 and 5 wt %. The samples are accelerated aged under UV, temperature, humidity and electric stress. Flashover tests have been carried out under dry and rainy conditions reveal 3 wt % of MgO have better breakdown voltage in virgin and aged specimens. SEM/EDAX shows fair distribution of nano MgO particles in the polymer base matrix. Fourier transform infrared spectroscopy [FTIR] of virgin and aged specimens indicate 3 wt % has least % of variation in properties of aging resistance, degradation resistance, hydrophobicity, oxidation resistance and erosion resistance. Water absorption test was done to further ascertain the hydrophobic property. The good Si–O–Si bond, better hydrophobicity, resistance to formation of oligomers, fair distribution of nano MgO into the polymer base are the prime factor attributing to the enhanced performance of aged 3 wt % MgO under dry and rainy flashover conditions. This makes it one of the best alternative for outdoor insulation.