Thermal properties of poly(dimethyl siloxane) nanocomposite filled with silicon carbide and multiwall carbon nanotubes

Silicon carbide was incorporated in poly(dimethyl siloxane) (PDMS) in combination with multiwall carbon nanotubes (MWCNTs) to improve the thermal conduction behavior. The amount of silicon carbide was increased from 0 to 150 phr and the amount of MWCNTs was increased from 0 to 8 phr at a fixed amount of silicon carbide (150 phr). The thermal conductivity of the PDMS composite was increased with increasing amount of the MWCNTs and fine dispersibility of the incorporated MWCNTs was achieved without pretreatment. The rheological properties of the PDMS composites incorporating silicon carbide and MWCNTs were investigated and the activation energy of the composites was calculated during thermal decomposition using the Horowitz-Metzger method. Importantly, unexpected thermal decomposition behavior as indicated by the reduction in activation energy from 361.63 to 194.18 kJ mol ^-1, namely acceleration of decomposition of the PDMS matrix caused by MWCNTs, was observed for the first time. SiC/MWCNTs filled PDMS nanocomposites were prepared and their properties were investigated. Thermal conductivity was improved with the addition of fillers, however, the acceleration of decomposition of PDMS by MWCNTs was observed.