Synergetic enhancement of thermal conductivity in the silica-coated boron nitride (SiO2@BN)/polymethyl methacrylate (PMMA) composites

Abstract

High thermal conductivity polymer composites have increased application in modern electronics. To achieve high thermal conductivity at relatively low filler content, two critical approach are used: surface modification of the filler and construction of thermal conductive network in polymer composites. This article provided a new simple and feasible method to modify h-BN consisting of physical absorption of polyvinylpyrrolidone (PVP) and hydrolysis of tetraethyl orthosilicate (TEOS). Then, SiO2@BN/PMMA composites were fabricated via solution-mixing and hot compression. The surface modification of BN enhanced the interface interaction between adjacent BN, which led to reduced thermal resistance and phonon scattering. The solution-mixing and hot compression process ensured the formation of thermal conductive pathway at the same time. The highest thermal conductivity of 40 vol% SiO2@BN/PMMA composite reached 5.583W /m K, which exhibited 3292% and 200% enhancement compared with the pure PMMA and melt-mixing BN/PMMA composites, respectively.