Synthesis, Characterization and Optical Properties of Oxidized Poly Vinyl Alcohol

Abstract

Poly (viny1 alcohol) (PVA) was partially oxidized by alkaline KMnO4 with an average carbonyl percentage of 65 %. PVA's photo physicochemical properties before and after the oxidation (OPVA) were investigated. The FTIR spectrum of OPVA revealed a new band at 1645 cm−1, corresponding to the carbonyl group and the XRD pattern reflecting an increase in the degree of crystallinity. Unlike pristine PVA, the UV-vis absorption spectra displayed the most attractive results through OPVA absorption in UV and visible regions. Furthermore, the photoluminescence spectra of PVA membrane exhibited a narrow emission at 338 nm, whereas the OPVA membrane showed blue emission at 415 nm. The proton conductivity increased from 1.5 mScm−1 in PVA to 11.1 mScm−1 in OPVA at 70 °C. Thus, the presence of both hydroxyl and carbonyl groups in OPVA results in the formation of strong hydrogen bonding that facilitate proton transfers along the hydrogen-bond network.