A Full-component recyclable Epoxy/BN thermal interface material with anisotropy high thermal conductivity and interface adaptability

Thermal interface materials (TIMs) with excellent heat dissipation capacity are highly desired for the development of miniaturized, integrated, and dense electronic devices. In addition, with the increasing accumulation of e-waste, the recyclability of TIMs has also become an urgent concern. Herein, a fully recyclable TIM with high thermal conductivity and conformability to the rough surface was prepared based on the synthesized epoxy vitrimer and boron nitride (BN) nanosheet. Results revealed that only by simple hot-pressing, the filled BN could be easily oriented in the plane and led to a thermal conductivity of 3.85 W m-1 K-1 with the BN content of 40 wt %, which was 30 times higher than that of the pristine epoxy resin and 4.3 times higher than the composite before hot-pressing treatment. The electronic device made of the prepared composite exhibited a 20 degrees C lower core temperature than the commercial silicone material, due to the superior thermal conduction and mechanical compliance. Moreover, benefiting from the multistage degradation mechanism of the synthesized epoxy vitrimer, the fabricated composite could be efficiently chemically recovered under mild conditions, demonstrating the BN recovery rate of 96.2% and other organic raw materials recovery rate of 73.6% to 82.4%. This work provides us with a new strategy for the design of recyclable and high-performance TIMs.