The Thermal Conductivity and Electrical Properties of EP Composite With Different Size BN

摘要

Epoxy resin is one of the most widely used thermosetting polymers and commonly applied in electrical power engineering. The intrinsic properties of epoxy can be improved by the introduction of inorganic filler, thus fabricating a composite material. Boron nitride is a ceramic dielectric material with high electric breakdown strength and high thermal conductivity, while exhibiting a low relative permittivity. In this study we investigate the influence of the filler size and its concentration on the electrical properties and thermal conductivity of epoxy. Two types of composites were prepared with an average particle size of 1 μm and 10 μm and a filler concentration of 20, 30, 40, and 50 percent by weight. The surface of the particles was functionalized with a coupling agent in order to increase the compatibility of boron nitride and epoxy resin. The results show that the relative permittivity of the composite decreases more when introducing particles. The breakdown strength of epoxy resin added 30 wt% boron nitrides with size is 1 μm is higher than that of epoxy resin. The highest value of thermal conductivity was obtained for the composite containing 50 wt.% boron nitrides with average particle size of 10 μm, and the thermal conductivity is 1.52 W/m·k.