Structure, thermal conductive, dielectric and electrical insulating properties of UHMWPE/BN composites with a segregated structure

Abstract

In recent years, Polymer - based thermal conductive composites have acquired a great industrial and commercial interests for decades, attracted much attention of numerous researchers. In this study, Boron nitride(BN) and ultra high molecular weight polyethylene(UHMWPE) composites with a segregated structure are prepared by binder-mixing method aiming at highly thermally conductive polymer composites, accompanying excellent dielectric and electrical insulating properties. The continuous and homogeneous thermally conductive networks originated from the segregated structure provide a guarantee for the high thermal conductivity of the composites. When the volume fraction of BN was 25.93 vol%, the thermally conductive coefficient of UHMWPE/BN composites are improved to be 5.7 Wm−1 k−1, showing an immense improvement compared with pure UHMWPE, the dielectric constant of 3.66 under 1 MHz, and the volume electric resistivity was 8.0 × 1014 Ω.cm at room temperature. These properties indicate its potential application in microelectronic devices. Hashin-Shtrikman model fitting reveals BN has great ability to form continuous and homogeneous thermally conductive networks.