Influence of rigid particles on thermal conductivity enhancement of polydimethylsiloxane composite during spatial confining forced network assembly

In order to meet the heat dissipation requirements of electronic equipment, a variety of methods for preparing thermally conductive polymer composites have been proposed. In this article, highly thermal conductive polydimethylsiloxane (PDMS) composites were prepared by combining the spatial confining forced network assembly (SCFNA) method with adding rigid particles (RPs). The orthogonal experiments were designed to verify the effects of short carbon fiber (SCF) content, glass bubble (GB) content, GB particle size and composite thickness on the thermal conductivity (lambda) of SCF-GB/PDMS composite. In addition, the lambda and shapes of different RPs (including GB, SiO2, AlN, glass fiber [GF]) also play vital roles in lambda enhancements of SCF-RP/PDMS composites. The mechanical properties of SCF-RP/PDMS composites were different with various RPs contents, and the SCF-GB/PDMS composite presented the largest elongation at break (70%) and the best mechanical flexibility. The SCF-GB/PDMS composite with a low GB content of 5 vol% can not only greatly improve the lambda, but also ensure its excellent mechanical properties.