Polyphenylsulfone-hBN Composite Insulation

The goal of this work was to develop and characterize high-temperature, thermally conductive electrical insulation to improve thermal management in high power density electric motors. Polyphenylsulfone (PPSU) films were extruded with up to approximately 24 wt% of either micro-sized hexagonal boron nitride (hBN) or a mixture of micro-and nano-sized hBN particles. The effect of hBN concentration and filler type on the dielectric breakdown voltage, frequency-and temperature-dependent electrical properties, thermal conductivity, and thermal aging behavior were investigated.