An eco-friendly, slow-resilience hBN composite as a high-performance and recyclable thermal interface material

Thermal interface material (TIM) composites composed of hexagonal boron nitride (hBN) fillers with high thermal conductivity and mechanical slow resilience properties have been shown to be effective solutions for increasing the demand for electronic device heat dissipation. However, the use of polymers or resins as the TIM matrix is costly for recycling or causes severe environmental pollution due to the long period of degradation. Additionally, the hBN filler normally has a much higher cost than the matrix does. Thus, the search for environmentally friendly and cost-effective recyclable hBN-based TIM composites is promising. Here, we develop a malleable and easily processable hBN/starch composite dough through a cost-effective and scalable fabrication process. The prepared composite exhibited a high thermal conductivity of 4.30 W m −1 K −1 (at 40 wt% hBN loading), good thermal stability and good mechanical compliance properties with stable slow resilience. The resulting TIM ensures seamless contact between the heat source and heat sink, which contributes to effectively enhanced heat dissipation. Excellent antibacterial properties are also demonstrated by the addition of a small amount of glycerol or tannic acid to the TIM. The hBN fillers can be recycled at a high recovery rate of 96.1 % with a low process cost. Our work provides a novel and practical strategy for developing high-performance and low-cost TIMs for thermal management applications.