Adjustable boron nitride segregated framework in epoxy resin for high performance thermal management and flame retardant applications

Excess heat production in miniaturized and integrated of electronic devices has created a strong demand for polymeric thermal management materials with superior thermal conductivity and flame retardancy. For the reason, a phytate-assisted ball-milling method was used to exfoliate and functionalize the boron nitride nanosheets (f-BNNS) with flame retardancy, which was further modified using KH560. Then, EP composites with f-BNNS@KH560 frames were prepared by emulsion polymerization, adhesive self-assembly and hot-pressing strategies. The mass ratio of EP to water in the emulsion polymerization process is closely related to the structure of f-BNNS@KH560 framework. The smaller the ratio of EP to water, the more complex the structure of the framework and the more paths for heat transfer of the obtained EP composites. Ultimately, f-BNNS@KH560/EP-3 exhibits a high K value of 2.4 W m−1 K−1 at a loading of 30 wt% due to more abundant heat transfer paths and good compatibility. In the cooling performance test of LED lamp, f-BNNS@KH560/EP-3 works at a temperature 16.5 °C lower than that of conventional f-BNNS@KH560/EP composites. Besides, the superior flame retardancy of f-BNNS@KH560/EP is mainly attributed to the strong barrier effect of adjustable f-BNNS@KH560 framework. Undoubtedly, f-BNNS@KH560/EP-3 provides ideas for industrial applications of high power devices.