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Polymer composites with polystyrene (PS) as matrix and (Ba0.5Sr0.4Ca0.1)TiO3 (BSCT) as fillers are prepared by solution casting method. It is found that the dielectric constant of the prepared BSCT/PS composites increases with increasing filler content over the frequency range from 100 Hz to 500 MHz. And the dielectric properties of the composites show a good temperature independency over the range of −30°C to 80°C. For the composite with 50 vol % filler content, the dielectric constant and dielectric loss are comparable with the literature values reported for other PS composites used for microwave substrate. Several theoretical models are used to compare with the experimental data of the dielectric constant of the composites. The microstructure and thermal properties of the composites were also studied. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41398.

Poly(vinylidene fluoride) (PVDF) and (Ba0.5Sr0.4Ca0.1)TiO3 (BSCT) are used as matrix and fillers, respectively, to prepare polymer functional composites by solution casting with N,N-dimethyl formamide as a solvent. It is found that the addition of BSCT has significant influence on the crystallization, melting, and glass transition behaviors of the PVDF matrix. The dielectric properties of the BSCT/PVDF composites are studied over a wide frequency range from 100 Hz to 1 GHz and a wide temperature range from −50 °C to 100 °C to explore the dependences of frequency and temperature. High dielectric constant (ɛ) up to 132 at 100 Hz and low dielectric loss (tan δ) down to 0.0045 at 1 GHz are achieved for the BSCT/PVDF composites. The obtained data of e are also theoretically fit by different models, and the modified Lichtenecker equation and Jayasundere-Smith equation show the best match.