Improving dielectric properties and thermal conductivity of polymer composites with CaCu3Ti4O12 and beta-SiC hybrid fillers

摘要

In this paper, we report a series of homogeneous polymeric composites with enhanced dielectric properties and thermal conductivity. The composites were constituted of polyvinylidene fluorides (PVDFs) matrix and CaCu3Ti4O12 (CCTO) monolithic or CCTO/beta-SiC hybrid fillers, and prepared by simple melt blending and hot moulding technique. The influence of different types of fillers and their composition on the dielectric response and thermal conductivity of the obtained composites was studied. Results show that hybrid loading is preferred and a reasonable combination of thermal conductivity (0.80W. m(-1) . K-1), dielectric constant (similar to 50) and dielectric loss (similar to 0.07) at 103 Hz was achieved in the PVDF composite containing 40 vol.% CCTO and 10 vol. % beta-SiC. The strong dipolar and interfacial polarization derived from the fillers are responsible for the enhancement of the dielectric constant, while the formation of thermally conductive networks/chains by beta-SiC whiskers contributes to the improved thermal conductivity.