Flexible PVC/BT (Polyvinyl chloride/Barium Titanate) composite thick films with (0-30%) volume fractions of BaTiO3 were fabricated via the solution casting method. The effects of BaTiO3 filler on the phase, microstructure and dielectric properties of composite films were investigated. The XRD results revealed that BT particles are embedded in the PVC matrix with no chemical reaction taking place between the two phases. It was observed that the glass transition temperature of PVC had increased with the addition of BT. The frequency dispersion in the dielectric constant versus temperature curves indicated the relaxor nature of the composites. The dielectric constant (εr) measured at 40 °C, increased from 7.6 for pure PVC to 16.1 for 30% of BaTiO3 content in PVC polymer matrix. It is suggested that BaTiO3 ceramic powder enhanced the dielectric properties of PVC and may be used as a flexible dielectric material.
Keywords: PVC/BT; composites; dielectrics; perovskites; polymer.