Dielectric properties of epoxy based nanocomposites for high voltage insulation

Epoxy polymer with micro, nano and micro + nano silica fillers have been evaluated for their electrical performance in high voltage insulation applications. The dielectric strength of these samples was measured in accordance with the ASTM D-149 standard. Dielectric spectroscopy was used to understand the role of space charge and interfaces in these materials. The results of dielectric spectroscopy suggest that significant improvement in the electrical performance can be expected by using samples containing nanofillers and micro + nanofillers when compared to materials containing only microfillers. However, the dielectric strength measurement showed no statistically significant improvement for the nanofilled samples. Techniques other than dielectric breakdown may be required to adequately characterize differences in the electrical performance of the dielectrics. For example, a partial discharge test using a highly non-uniform field may be more useful as it would correspond to simulate actual service conditions.