Improvement of polylactic acid electret properties by addition of fine barium titanate

The effect of BaTiO3 on properties of polylactic acid composites was studied. Measurements of surface potential, electric field strength, effective surface charge density, and isothermal and thermally-stimulated potential relaxation showed that corona-charged films of the PLA – BaTiO3 composites had more stable electret properties compared to PLA films. Addition of BaTiO3 particles resulted in higher thermal stability of the charge, but it did not affect transition temperatures in the polymer according to differential scanning calorimetry data. IR-spectra revealed that filler addition accounted for disappearance of the charge–dipole complex bands. Homo- and heterocharge depth in the material was studied as well.