An investigation into improving the breakdown strength and thermal conduction of an epoxy system using boron nitride

It has been seen previously that addition of fillers to host material systems can create composites with superior properties. In particular polymers have been shown to be good hosts for such property-boosting fillers. This investigation looks at such a polymer based nanocomposite, with the aim to produce a thermally conductive high voltage insulator. A standard thermosetting epoxy system and hardener were chosen to act as the host polymer due to its good initial mechanical and electrical properties. This system has also been successfully used previously to host other fillers. The filler chosen was boron nitride powder, due to its claim of having good insulation properties and high thermal conductivity. Several different sizes and aggregation states of boron nitride were tested and it was hoped that successful dispersion of the fillers would not only increase the breakdown strength of the material, but also the thermal conductivity.