PVDF/BaTiO3 composites as dielectric materials: Influence of processing on properties

In this work 0-3 connectivity composites based on poly(vinylidene fluoride) (PVDF) and containing 30 vol% of BaTiO3 nanoparticles were prepared by using two different processing methods: solvent casting and melt blending. In both cases, the ensuing composite materials were compression molded to obtain sheets suitable for the subsequent characterization. In order to induce the formation of the electro-active ? polymorph of PVDF, the compression molding conditions were properly adjusted. A thorough characterization was then performed to investigate the influence of processing conditions on the dielectric properties of the composites, taking into account PVDF polymorphism and particles dispersion within the polymer matrix. Experimental evidences suggest that dielectric characteristics of the composites are strongly affected by the processing procedure; in particular, composites from melt blending with high amounts of ? phase have higher permittivity values compared to those obtained from solvent casting, probably due to a synergistic contribution of PVDF polymorphism and morphological features