Fabrication and properties of PVDF/BaTiO3 nanocomposites for electronic applications

In this project, polymer matrix nanocomposites based on poly(vinylidene fluoride) (PVDF) as matrix and nanobarium titanate (BaTiO₃) as reinforcement were fabricated using hot pressing at 200 °C and 45 MPa. The BaTiO₃ content was varied from 0 to 50 wt% (~ 23 vol%) in the PVDF matrix. Nanocomposites were characterized to get information about topography, density, microhardness and dielectric properties. Scanning electron microscope showed almost uniform dispersion of nanoBaTiO₃ in the matrix. However, some aggregates of BaTiO₃ were also observed due to Van der Waal´s force. The experimental density was very close to that of theoretical density. The microhardness was increased with increasing BaTiO₃ content in the matrix. A 50 wt% BaTiO₃ nanocomposite showed Vickers microhardness of 9.7 kg/mm² compared to that of pure PVDF (7.3 kg/mm²). The dielectric constant of nanocomposites increased by more than 3-fold and it decreased slightly with increasing frequency from 1 kHz to 15 MHz. The significant improvement in microhardness and dielectric constant was attributed to the better dispersion of BaTiO₃ in the matrix.