Synergistic enhancement of thermal conductivity between SiCw and h-BN in MVQ-based composite

Abstract

Thermally conductive and electrically insulating h-BN/MVQ and h-BN/SiCw/MVQ composites were prepared by internal mixing and two roll mixing, using 1-dimensional (1D) silicon carbide whiskers (SiCw) and 2-dimensional (2D) hexagonal boron nitride flakes (h-BN) as fillers, and methyl vinyl silicone rubber (MVQ) as polymer matrix. Surface modification of 1 D SiCw and 2 D h-BN was characterized by Fourier transform infrared spectroscopy (FT-IR) and contact angle analysis. Morphology, thermal conductivity and dielectric constant of h-BN/MVQ and h-BN/SiCw/MVQ were studied. The results indicated that surface modified h-BN and SiCw could be uniformly distributed in MVQ matrix. At the same volume filler loading, thermal conductivity of h-BN/SiCw/MVQ ternary composite was higher than that of h-BN/MVQ binary composite. When part of 2 D h-BN was instead of 1 D SiCw, there was synergistically enhanced effect between 1 D SiCw and 2 D h-BN for thermal conductivity. When volume ratio of h-BN/SiCw was 8/2, thermal conductivity of h-BN/SiCw/MVQ was higher than that of other ratio. Thermal conductivity of h-BN/SiCw/MVQ composite with different volume ratio was linearly fit with Agari’ model.