An investigation on conductivity and dielectric behaviour of neem gum blended PVA biopolymer electrolytes

Abstract In this article, a neem gum-based polymer electrolyte is synthesised using the solution casting approach. XRD, FTIR, and AC impedance analysis are used to investigate the structural and electrical properties of bio-gel polymer electrolytes (BGPEs) that have been synthesized. According to XRD analysis, the film is more amorphous at 60 wt % PVA: 20 wt % NG: 20 wt % NaCF3SO3 (BP2). The observed amorphous nature is due to a greater number of Na+ and CF3SF3– ions coordinated with the polymer side chains’ COO– and OH– groups. The FTIR analysis revealed the disappearance of CH2 wagging of pure Poly (vinyl alcohol) (PVA) and shifting of stretching vibration mode of (C – N) aromatic functional group of protein of pure neem gum (NG) due to complexation of blended polymer (PVA: NG) with Na ions. The conductivity of the produced films is analysed using the conductance spectra, and the film BP2 (60 wt % PVA: 20 wt % NG: 20 wt % NaCF3SO3) is found to have the highest ionic conductivity (≈ 5.328 x 10-4 Scm-1) at 303 K. Flexibility, hopping mechanism are well enhanced in host polymer (PVA: NG) due to the addition of ionic salt NaCF3SO3, which is clearly observed in the dielectric spectra. GRAPHICAL ABSTRACT