Construction of hexagonal boron nitride@polystyrene nanocomposite with high thermal conductivity for thermal management application

Hexagonal boron nitride (BN) hold great promise as emerging building blocks for thermal interface materials owing to their outstanding heat transfer performance. Herein, we report a carboxylated polystyrene-coated hydroxylated BN (BN-OH@PS-COOH) nanocomposite with highly thermal conductivity (TC) and extraordinary mechanical properties for thermal management. The exfoliated BN-OH nanosheets were obtained via molten alkali hydroxide pretreatment and sonication. Subsequently, PS-COOH nanospheres were grew on the surface of BN-OH nanosheets by in situ polymerization. Noncovalent interactions between PS-COON and BN-OH are favor to reduce interfacial thermal resistance, which contributes to accelerate heat transport. As a result, the TC of the resultant BN-OH@PS-COOH nanocomposite with 12 wt% BN-OH addition is 1.131 W/mK, which is much higher than that of neat PS (0.186 W/mK) and BN/PS blend nanocomposite (0.312 W/mK). Moreover, the BN-OH@PSCOOH nanocomposite exhibits outstanding mechanical properties. Our study may stimulate novel perspectives on the design of high-performance polymer-based thermal interface materials.