Construction of self-lapping three-dimensional thermal conduction network in epoxy resin thermosets by incorporating “dendritic” zinc oxide derived from metal-organic framework

Abstract

Thermal management materials are the solution to heat dissipation issues in electronic devices, which are considered vital to the device's reliability and lifetime. Therefore, it was of great significance to develop a new type of epoxy resin composites with flame retardant, thermal conductivity and toxicity reduction. Here, dendritic zinc oxide (D-ZnO) was designed and synthesized after annealing the metal-organic framework (MOF) precursor and then using it to fabricate a thermally conductive epoxy resin (EP) thermoset. The synthesized d-ZnO reached a high specific surface area of 40.389 m2g−1, which is about 14 times higher than that of commercial ZnO (C-ZnO). Remarkably, the EP/D-ZnO thermosets reaches a thermal conductivity (TC) of 1.10 Wm−1K−1 at a low filler loading of 10 wt%, which is more than 4.5 times more than pure EP. In the meantime, the TC of the d-ZnO composite was 120 % higher than that of the commercial ZnO composite at the same loading. The coefficient of thermal expansion (CTE) of EP/10wt% d-ZnO thermoset decreased by 68.6 ppm K−1 compared to pure EP. The excellent thermal diffusion performance could be attributed to the polarized interfaces of d-ZnO, which forms heat conduction pathways. Thus, with addition of functionalized d-ZnO, the peak CO production and peak CO2 production were decreased from 0.036 gs−1 and 0.80 gs−1 for pure EP to 0.026 gs−1 and 0.50 gs−1(EP/D-ZnO thermosets). The EP/D-ZnO thermosets reported by this strategy demonstrate great potential as next generation thermal management materials.