Characterization of H3PO4 based PVA complex system

Abstract

In this communication, thin films of polyvinyl alcohol (PVA) complexed with H3PO4 of different stoichiometric ratios have been characterized using various experimental techniques, namely IR, NMR and X-Ray Diffraction. Comparing the characteristic behaviour of pure and complexed PVA, it is observed that there is appearance of a new spectral band (IR), some new atomic planes in addition to variation in relative intensity (X-ray diffraction) and change in chemical shift along with change in intensity (NMR) which all confirm the formation of PVA-H3PO4 complexes. It is found that the amorphous character of PVA complexes increases with H3PO4 concentration which governs the magnitude of conductivity of polymer complexes. The ionic transference number of mobile ions has been estimated by Wagner's polarization method and the value is reported to be tion ≃ 0.97. The Transient Ionic Current (TIC) measurement technique has been used to detect the type of mobile species and to evaluate their mobilities. The mobility of H+ cation has been calculated and found to be μH . ≃ 1.3 × 10-4 cm2 V-1 s-1.