Preparation and dielectric properties of poly(vinylidene fluoride)/Ba_0.6Sr_0.4TiO₃ composites

Highlights: • When the BST particles are mixed with PVDF polymer, hydrogen bond will form between the F atoms on the PVDF and the –OH groups on the surface of the BST particles. • The permittivity of PVDF+40 vol% BST composites is 190 at 1 kHz at 160 °C and the tunability amounts to 7.2% under the bias voltage of 1.0 kV/mm at 10 kHz. • The breakdown strength decreased with BST fillers increasing and the energy storage density of PVDF+40 vol% BST composites was about 0.36 J/cm³. - Abstract: The poly(vinylidene fluoride) (PVDF)/barium strontium titanate (BST) composites were fabricated by solution casting method. The microstructure and dielectric properties of composites comprising polyvinylidene fluoride (PVDF) and barium strontium titanate (BST) particles have been investigated. It was found that the permittivity of the BST/PVDF composites increases from 16 to 40 while loss tangent decreases from 0.27 to 0.19 with BST fillers increasing from 10 vol% to 40 vol%. The tunability of PVDF + 40 vol% BST composites was 7.2% under the bias voltage of 1.0 kV/mm and the energy density was 0.36 J/cm³, making it suitable for embedded capacitor applications. The dielectric properties of PVDF were improved by increasing BST fillers and studying the mechanism of interface reaction