Structural, optical and some physical properties of PVDF films filled with LiBr/MnCl2 mixed fillers

Films of polyvinylidene fluoride (PVDF) filled with (X)LiBr(20-X)MnCl2 mixture, where X=0, 1, 2, 8, 16 and 20 wt%, were prepared by casting method and studied by ultraviolet/visible optical absorption (UV), differential scanning calorimetry (DSC), X-ray diffraction (XRD), infrared transmission (IR) and electron spin resonance (ESR). The optical absorption spectra suggested the presence of an optical gap (E-g) which depends on filler concentration (W) and arises due to the variation in crystallinity within the polymer matrix. Melting and degradation temperatures were identified using DSC. XRD implied a semicrystalline structure (containing alpha- and beta-PVDF phases for all films). Conjugated double bonds and the role of dimethylformamide with a PVDF chain were detected by IR spectra. The ESR analysis revealed the existence of both isolated and aggregated Mn2+ ions within the PVDF matrix. Published by Elsevier B.V.