High Elasticity and Stability of Thermally Conductive Composites Offered by Disulfide Exchange-Based Silicone Elastomers

Abstract

Due to its excellent flexibility, silicone-based materials are widely used in the thermal management of modern electronic devices, but they still face risks of cracking and silicone contamination. In this work, a silicone elastomer (EPHMS) is achieved through the cross-linking between a synthesized epoxy-terminated PDMS and 4-aminophenyl disulfide (APD). The synthesized EPHMS demonstrates exceptional elasticity and thermal stability, showing a 98% recovery efficiency and no detectable silicone migration under sustained compressive strain. Additionally, it possesses an initial thermal degradation temperature of 285 °C. The disulfide exchange endows EPHMS with self-healing and reprocessing capabilities. Boron nitride (BN) fillers were further incorporated into the matrix to enhance the thermal conductivity of EPHMS. The composite achieves a thermal conductivity of 2.70 W m^–1 K^–1 when the mass fraction of BN is 40%, and it retains as high as a 97% recovery rate in compression tests. As indicated, the composite also exhibits self-repairing and reprocessing abilities. This work points to a new path for developing elastic and stable thermally conductive materials.