Synthesis and characterization of Ultra High Molecular Weight Polyethylene filled with boron nitride micro and nano-particles

In this work, the effect of particle size on dielectric, electrical and thermal properties of highly charged (50 wt.%) h-BN micro and nano-filled Ultra High Molecular Weight Polyethylene (UHMWPE) samples was investigated. The dielectric properties of the composite samples were characterized using dielectric spectroscopy. The permittivity of the composites was found to remain relatively low and no significant change was observed between micro and nano-sized fillers. The thermal conductivity of UHMWPE was largely improved by the addition of BN fillers. On the other hand, a decrease in the short-time breakdown strength was observed for both the micro and the nano composites. This could be attributed to the presence of voids or defects between the fillers and the polymeric matrix. In the case of the nanocomposite, the dielectric breakdown strength was found to be close to that observed for the neat UHMWPE case, indicating that the presence of nanoparticles may possibly reduce the negative impact of having an inorganic filler within the PE matrix. The corona resistance of both micro and nano composites was greatly improved.