Microstructure and dielectric properties of poly(vinylidene fluoride)-based composites introduced by molecule organic benzoic acid

Polymer materials are indispensable materials for modern social life and industrial production. To meet more performance requirements, in addition to synthesizing new polymers, polymer composites have become one of the current research hotspots for polymer materials due to their excellent physicochemical property. Benzoic acid/polyvinylidene fluoride (BA/PVDF) composites were prepared by melt blending method after the modification of polyvinylidene fluoride (PVDF) with small molecule organic benzoic acid. The crystal structure, crystallinity, and melting behavior of the composites were characterized by XRD, FTIR, and DSC. It was found that BA could promote the formation of the γ crystal form of PVDF, and reduce the crystallinity and melting temperature. Dielectric relaxation spectra and hysteresis loops characterize the dielectric properties, relaxation behavior, and energy storage properties of the composites. The breakdown field strength, energy storage efficiency, and energy storage density of the composites were improved.