Effect of Micro-Scale and Nano-Scale Boron Nitride on Thermal Property of Silicone Rubber Via Experimental and Simulation Method

With the development of electronic integration, excellent insulation and high thermal conductivity thermal interface materials (TIMs) are needed to be used. Most of currently reported TIMs have high thermal conductivity, but their processing is complex and not suitable for industrial application. In this work, a simple method is provided to prepare thermally conductive silicone rubber (SR) composites. Effects of size and ratios of micro-scale boron nitride (BN) and nano- scale BN on mechanical properties, thermal conductivity and thermal stability of SR/BN composites are investigated. Results show that when the ratio of micro-scale BN loading to nano-scale BN loading is equal and the loading of BN are 60 phr, the thermal conductivity of SR/BN composites reaches to 2.632 W/(m·K), which is 18 times higher than that of SR. Meanwhile, when the loading of micro-scale BN is twice than that of nano-scale BN, the SR/BN composites maintain good mechanical properties (the tensile strength reaches to 6.2 MPa). In addition, the SR/BN composites exhibit excellent thermal stability and the heat loss of all samples are nearly 45%. This can provide a new idea for a simple and effective preparation of the SR/BN composites with a high thermal conductivity and insulating.