Preparation and properties of PST-PT/PVDF composite materials

By use of compression modeling/sintering technique, a series of PST-PT/PVDF composites of different constitutions were prepared using a self-made model. SEM results show that the PST-PT ceramic particles dispersed equally in polymer. Dielectric properties of composites containing PST-PT dispersed in PVDF matrix having 0-3 connectivity were measured. The results indicate that the dielectric constant was strongly influenced by the relative proportions of the two constituents, temperature and frequency. The dielectric constant in the ferroelectric phase of PST-PT plays an important role in controlling the effective dielectric constant of the PST-PT/PVDF composites, especially for the composite containing 9% (mass fraction) PST-PT. Different from other samples, it is remarkable that the addition of 9% PST-PT to PVDF results in the appearance of a large peak of dielectric constant near 60°C.