Morphological and dielectric properties of barium chloride‐filled poly(vinylidene fluoride) films

Abstract Morphological characteristics of poly(vinylidene fluoride) (PVDF) films, filled with mass fractions (w ≤ 20%) of Barium Chloride (BaCl₂), were investigated by X‐ray diffraction (XRD), Fourier transform infrared (FTIR) absorption spectra and differential scanning calorimetry (DSC) measurements. The dielectric properties of films were measured from 250 Hz to 1 MHz range between 100 and 400 K as a function of frequency and temperature. Spectroscopic data revealed that the filled and unfilled films include α‐, β‐, and γ‐crystalline phases. By a 20% filling, 73% increase was obtained in the total degree of crystallinity. Since the BaCl₂ formed fluorine bridges over the chain segments on the crystal lamellar surface, the γ‐crystalline phase decreased, whereas the total degree of crystallinity increased. Dielectric measurements showed that maximum of the dielectric loss factor belonging to β‐relaxation transition decreased linearly with filling level. The filling process did not have any effect on the real dielectric constant till α‐relaxation transition region. However, in the α‐relaxation transition region, it was determined that the real dielectric constant increased linearly with filling level. POLYM. COMPOS., 31:1782–1789, 2010. © 2010 Society of Plastics Engineers.