Dielectric and Thermal Properties of Polylactic Acid/Barium Titanate Composites

Composites of polylactic acid matrix and spherical sub-micrometer barium titanate particles were prepared using extrusion. Filler dispersion, thermal properties and dielectric spectroscopy of the prepared were characterized. Results reveal that thermal properties of the composites dos not have significant correlation with filler concentration. The dielectric constant at 50 Hz of the composites is increased while the dielectric loss remains on the 10
⁻³
order of magnitude. From the dielectric spectroscopy results, it could be summarized that the dielectric response of PLA composites shows different patterns in the glassy state (when temperature is below the glass transition temperature of PLA matrix) and high-elastic state (above the glass transition temperature), which is dielectrically stable in the glassy state and has a relaxation polarization phenomenon in the high-elastic state.