Synthesis, Characterization and Optical Properties of Oxidized Poly Vinyl Alcohol

Abstract

Poly (viny1 alcohol) (PVA) was partially oxidized by alkaline KMnO 4 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 À 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. Further-more, 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 À 1 in PVA to 11.1 mScm À 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.Density functional theory (DFT) investigation on PVA and OPVA oligomers confirmed that the oxidation induces a significant change on the frontier's orbitals, resulting in a decrease in the dipole moment (μ) and an electronic bandgap in the ground state. Indeed, the detected results for OPVA are promising for optoelectronic applications.

Augmentation in proton conductivity of crosslinked poly(vinyl alcohol) through the introduction of polyvinyl pyrrolidone

“…The spectral profile of PVA is characterized by the presence of bands at 3398 cm −1 (OH stretching of PVA), 2928 cm −1 (CH asymmetrical stretching), 2864 cm −1 (CH 2 symmetrical stretching), 1653 cm −1 (CO stretching from the residual acetate group), 1462 cm −1 (CH scissoring) 1327 cm −1 (the deformation vibration of CH 2 ), 1101 cm −1 (COC stretching of the acetyl groups), and 843 cm −1 (CH rocking) 23 . The PVP profile showed two characteristic bands at 1680 cm −1 and 1283 cm −1 , corresponding to the stretching vibration of the CO groups and the stretching vibration of the CN groups in the PVP backbone, respectively 24 .…”

Preparation and characterization of polymeric Schiff's base for carbon dioxide adsorption

“…The XRD pattern of PVA reveals a distinct peak at 2θ=21°, corresponding to the (101) plane, [27] indicating the semi‐crystalline nature of PVA. This semi‐crystallinity arises from the intermolecular hydrogen bonding among the PVA chains, resulting in a partial ordering of the polymer chains.…”

“…The literature extensively documents the preparation of oxidized polyvinyl alcohol through different processes that partially or completely introduce carbonyl functionalities by oxidizing hydroxyl groups. [21,27,28] Lu et al reported the solid-state oxidation of PVA using hydrogen peroxide and [19][20][21][22] copper(II). [29] Lin et al investigated the degradation of PVA in aqueous solutions under 365 nm UV light in the presence of persulfate, noting higher PVA oxidation in acidic solutions than alkaline solutions.…”

“…Given the highly reactive nature of the hydroxyl groups in PVA, chemical modifications such as oxidation, [19–22] esterification, [23] acetalization, [24] ketalization, [25] and aldolization [26] are possible. The literature extensively documents the preparation of oxidized polyvinyl alcohol through different processes that partially or completely introduce carbonyl functionalities by oxidizing hydroxyl groups [21,27,28] . Lu et al.…”

Synthesis of polymeric Schiff bases and their application in carbon dioxide adsorption

“…are possible for PVA. The preparation of oxidized polyvinyl alcohol by adopting different processes, leading to partial or complete formation of carbonyl functionalities through the oxidation of hydroxyl groups, is well documented in the literature [21,27,28]. Lu et al have reported the solid-state oxidation of PVA using hydrogen peroxide and [19][20][21][22] copper (II) [29].…”