Constructing a High-Density Thermally Conductive Network through Electrospinning–Hot-Pressing of BN@PDA/GO/PVDF Composites

Polymer matrix composites with high thermal conductivity and elastic mechanical properties are promising materials for diverse practical applications. Herein, BN@PDA/GO/PVDF (PG) composite materials with a highly dense thermally conductive network were prepared by combining electrospinning and hot-pressing methods. Dopamine was used to modify hexagonal boron nitride (h-BN). The π–π interaction between the crystal plane structure of h-BN and the benzene ring in the polydopamine (PDA) structure can increase the surface adhesion of polyvinylidene fluoride (PVDF) fibers, thereby reducing the thermal resistance of the interface between the filler and polymer matrix. The contact per unit area was further improved by utilizing graphene oxide (GO) with a large specific surface area to clad the adhered fibers of BN@PDA. The thermal conductivity of PG60 was shown to be as high as 12.04 W/(m·K) owing to the increased density of the heat conduction path. It realizes the heat transfer from a point-to-point to a three-dimensional interconnected structure, implying that a synergistic effect is achieved. Moreover, when the mass ratio of BN@PDA to PVDF was 0.3 (P30), GO was added on the basis of P30. When the mass ratio of GO to BN@PDA was 1:8, PG30 was obtained. PG30 and P30 achieved tensile strengths of 26.65 and 23.38 MPa, respectively. This study provides an approach for designing a highly thermal conductive film with potential applications for the improvement of heat dissipation in electronic devices.