Dense graphene foam and hexagonal boron nitride filled PDMS composites with high thermal conductivity and breakdown strength

In the present study, high thermally conductive and electrically insulated polymer composites containing modified dense graphene foam (MGF) and modified hexagonal boron nitride (M-h-BN) via polydopamine (PDA) coating and 3-aminopropyltriethoxysilane (APTS) grafting were manufactured and studied. Due to the double percolated networks built by MGF and M-h-BN, the polydimethylsiloxane (PDMS) matrix composite has high thermal conductivity of 23.45Wm−1K−1 and 2.11Wm−1K−1 in in-plane and out-of-plane directions, respectively. In addition, an insulated layer of M-h-BN/PDMS can be introduced onto both sides of composite sample with the help of infiltration technique, which results in a high breakdown strength of 4.5 kV/mm. Owing to the excellent comprehensive properties, the M-h-BN/MGF/PDMS composite has a promising application in heat management field of the microelectronic industry.