Polymer/boron nitride nanosheet composite with high thermal conductivity and sufficient dielectric strength

An efficient method was reported to fabricate boron nitride (BN) nanosheets using a sonication-centrifugation technique in DMF solvent. Then non-covalent functionalization and covalent functionalization of BN nanosheets were performed by octadecylamine (ODA) and hyperbranched aromatic polyamide (HBP), respectively. Then, three different types of epoxy composites were fabricated by incorporation of BN nanosheets, BN-ODA, and BN-HBP. Among all three epoxy composites, the thermal conductivity and dielectric strength of epoxy composites using BN-HBP nanosheets display the highest value, efficiently enhancing to 9.81W/mK at 50vol% and 34.8kV/mm at 2.7vol% (increase by 4057% and 9.4% compared with the neat epoxy), respectively. The significantly improved thermal conductivity and dielectric strength are attributed to the large surface area, which increases the contact area between nanosheets and nanosheets, as well as enhancement of the interfacial interaction between nanosheets and epoxy matrix. Copyright (c) 2015 John Wiley & Sons, Ltd.