Microstructure and Dielectric Properties of PTFE-Based Composites Filled by Micron/Submicron-Blended CCTO

This paper investigated a polymer-based composite by homogeneously embedding calcium copper titanate (CaCu3Ti4O12; CCTO) fillers into a polytetrafluoroethylene matrix. We observed the composite filled by CCTO powder at different sizes. The particle size effects of the CCTO filling, including single-size particle filling and co-blending filling, on the microstructure and dielectric properties of the composite were discussed. The dielectric performance of the composite was investigated within the frequency range of 100 Hz to 1 MHz. Results showed that the composite filled by micron/submicron-blended CCTO particles had the highest dielectric constant (epsilon(r) = 25.6 at 100 Hz) and almost the same dielectric loss (tan delta = 0.1 at 100 Hz) as the composite filled by submicron CCTO particles at the same volume percentage content. We researched the theoretical reason of the high permittivity and low dielectric loss. We proved that it was effective in improving the dielectric property of the polymer-based composite by co-blending filling in this experiment.