Thermal degradation properties of solid polymer electrolyte (poly(vinyl alcohol)+phosphoric acid)/methylene blue composites
TL;DR: The thermal stability and degradation of poly(vinyl alcohol) (PVA), PVA+H 3 PO 4 (solid polymer electrolyte, SPE), pVA containing methylene blue (MB) dye and SPE+MB were studied by TG/DTA/DTG and DSC techniques as discussed by the authors.
About: This article is published in Polymer Degradation and Stability.The article was published on 2003-01-01. It has received 81 citations till now. The article focuses on the topics: Vinyl alcohol & Thermal stability.
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TL;DR: In this article, a good agreement of experimental FTIR spectra with the results of theoretical calculations of MB vibration modes was observed by means of the density functional theory (DFT/B3LYP/6-31-G(d)), using Gaussian-03 software package.
252 citations
TL;DR: In this paper, a polymer electrolyte based on PVA doped with different concentrations of NH 4 Br has been prepared by solution casting technique and the complexation of the prepared polymer electrolytes has been studied using X-ray diffraction (XRD) and Fourier transform infra red (FTIR) spectroscopy.
Abstract: Polymer electrolyte based on PVA doped with different concentrations of NH 4 Br has been prepared by solution casting technique. The complexation of the prepared polymer electrolytes has been studied using X-ray diffraction (XRD) and Fourier transform infra red (FTIR) spectroscopy. The maximum ionic conductivity (5.7×10 −4 S cm −1 ) has been obtained for 25 mol% NH 4 Br-doped PVA polymer electrolyte. The temperature dependence of ionic conductivity of the prepared polymer electrolytes obeys Arrhenius law. The ionic transference number of mobile ions has been estimated by dc polarization method and the results reveal that the conducting species are predominantly ions. The dielectric behavior of the polymer electrolytes has been analyzed using dielectric permittivity and electric modulus spectra.
218 citations
TL;DR: In this paper, polyaniline and poly( o -toluidine) doped with p-toluene sulphonic acid (p -TSA) were synthesized by in situ chemical polymerization method using ammonium per sulphate as an oxidizing agent.
113 citations
TL;DR: In this paper, an optimization of MMt-Na+ content up to 10% in PVA nanocomposite to obtain the properties required for organic solar cell encapsulation, namely an exfoliated structure that has high gas barrier properties, transparency, wettability and planarity of the surface.
97 citations
TL;DR: In this paper, the photochemical behavior of polyvinyl alcohol (PVA) films was studied under UV-visible light irradiation (λ > 300 nm) in accelerated aging conditions representative of natural ageing.
Abstract: Polyvinyl alcohol (PVA) is a water-soluble polymer that is anticipated to be a good candidate for incorporation into multilayer coatings of organic solar cells due to its high transparency and ability to form a barrier to oxygen. Because a long lifetime is a prerequisite for successful applications, it was necessary to study the photochemical behavior of PVA under solar light. PVA films were exposed to UV-visible light irradiation (λ > 300 nm) in accelerated aging conditions representative of natural ageing. Modifications in the chemical structure of aged samples irradiated at ambient air were recorded. Due to the low oxygen permeability of PVA films, it was shown that the photooxidative degradation of PVA films is restricted to the surface (<5 μm) and results in a large amount of chain scissions, with a progressive erosion of the surface of the irradiated material. The oxidation products formed along the macromolecular chains, and low molecular weight species trapped in the matrix or emitted in the gas phase were also identified. An oxidation mechanism was then proposed to account for these modifications. However, irradiation in the absence of oxygen demonstrated the high photostability of PVA films, which permits the use of PVA as a sublayer in inorganic/organic multilayer encapsulation systems.
92 citations
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TL;DR: In this paper, the authors used dynamic light scattering to obtain sterically-stabilized polyaniline dispersions in the presence of poly(vinyl alcohol) or poly(N-vinylpyrrolidone).
Abstract: When the oxidative polymerization of aniline proceeds in the presence of poly(vinyl alcohol) or poly(N-vinylpyrrolidone), sterically-stabilized polyaniline dispersions are obtained. The particles have an average diameter of about 300−600 nm as determined by dynamic light scattering. The yield of polyaniline in dispersion form often decreased if the reaction mixture was stirred during polymerization and dispersions were then accompanied by a macroscopic precipitate. Poly(N-vinylpyrrolidone) is a more efficient stabilizer compared to poly(vinyl alcohol). Microstructured composites, which contain up to ∼70 wt % of electrically-conducting polyaniline dispersed in an insulating matrix, can be prepared from these dispersions.
166 citations
TL;DR: The thermal decomposition of polyvinyl alcohol is known to occur in two stages as mentioned in this paper, and the main products were water, aldehydes having the general formula and methyl ketones having the formula, where n = 0, 1, 2, 3, etc.
Abstract: The thermal decomposition of poly(vinyl alcohol) is known to occur in two stages. In a study of first-stage decomposition, this polymer was pyrolyzed in vacuum at 240°C for 4 hr and the products were determined by using gas chromatography. The main products were water, aldehydes having the general formula and methyl ketones having the formula , where n = 0, 1, 2, 3, etc. Mechanisms for the formation of these carbonyl compounds are discussed.
151 citations