Improved performance of polyhedral oligomeric silsesquioxane epoxies

In high voltage applications, polymer insulation can be exposed to very high electrical field stress, resulting in long term exposure to corona. The electrical field stress may be much below dielectric breakdown threshold. Eventually the exposure to corona can lead to failure of the high voltage component. Nanometer sized inorganic fillers are increasingly used as reinforcing materials for mechanical or thermal property improvement of polymers. Improvements in mechanical modulus or heat deflection temperature are often realized. These fillers may also improve some electrical properties such as corona endurance in polymers. In the current study, polyhedral oligomeric silsesquioxane (POSS) loaded epoxies were produced and tested for corona endurance. Results suggest a five times improvement in ac corona lifetime of selected POSS-epoxies compared to unloaded epoxy.