PVDF-based composites containing PZT particles: How processing affects the final properties

Poly(vinylidene fluoride) (PVDF)-based composites containing up to 30 vol % of lead zirconate titanate (PZT) particles were prepared by: (a) different techniques, melt blending and solvent casting; and (b) different molding procedures, a single-step and a two-step hot-pressing method. The obtained samples were characterized in order to study how the processing affects their final properties. Results indicate that the different molding processes have a strong effect on polymorphism and molecular relaxations of PVDF as well as on dielectric response of the composite materials, that results enhanced by the two-step molding. The preparation technique influences the filler dispersion and, consequently, the elastic modulus of the composites, but without remarkably impacting on other properties. This suggests the possibility of preparing performing composites by a solvent-free and easily scalable technique (i.e., melt blending) and obtaining suitable dielectric characteristics, very important for application of such kind of materials, just by tuning the molding conditions.