Synergetic enhancement of thermal conductivity in the silica-coated boron nitride (SiO 2 @BN)/polymethyl methacrylate (PMMA) composites

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.