Preparation and properties of flexible dual-network high-performance epoxy composites

With the rapid advancement of highly integrated and high-power flexible electronic devices, there is an increasing demand for electronic packaging materials that effectively manage heat accumulation in electronic components. In this study, we prepared 3D boron nitride (BN)@polydopamine (PDA)/fluorinated graphene (FG)/epoxy resin (EP) dual network composites, PDBN4@FG3, with excellent thermal conductivity, good deformability, and dielectric properties, and electrically insulated. The thermal conductivity mechanism analysis based on finite element simulation shows that the 3D BN@PDA/EP foam skeleton prepared by the sucrose sacrificial template method is the first 3D network to form a continuous thermal conductive pathway. The FG/EP mixture was then infiltrated into the foam pores by vacuum impregnation, cured, and crosslinked to create a second 3D FG/EP network to enhance thermal conductivity synergistically. With a filler loading of only 11.9 wt%, the PDBN4@FG3 exhibits a thermal conductivity of 1.1598 W/(m⋅k), an impressive 479.9 % improvement compared to pure EP. Furthermore, PDBN4@FG3 exhibits optimal mechanical durability, outstanding capacity to regulate heat, and exceptional thermal stability. The extraordinary performance of 3D BN@PDA/FG/EP composites, which possess a flexible dual-network structure, makes them highly suitable for utilization in advanced electronic devices.