Oxidative polymerization of aromatic amines: kinetic features and possible mechanisms

Mezhuev, Ya. O.; Korshak, Yuri V.; Shtilman, Mikhail I.

doi:10.1070/rcr4755

Cited by 20 publications

(11 citation statements)

References 16 publications

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“…Regarding the reaction course, oxidation of aniline with APS in acidic aqueous media is not a step-growth polymerization because it is assumed that recombination of the radical cations of aniline n -mers with each other is virtually impossible, as they are insoluble in the reaction system and form a new phase. 2,5 However, this reaction is not a typical chain-growth polymerization consisting of initiation, propagation, and termination reactions as well. The oxidation of aniline with APS in acidic aqueous media can be monitored by the pH–time, temperature–time, and open-circuit-potential–time profiles of the reaction course.…”

Section: Introductionmentioning

confidence: 99%

“…2,6 Even though a PANI in emeraldine oxidation state is formed by this reaction at the APS-to-aniline mole ratio of 1.25, a higher PANI oxidation state called pernigraniline is formed as an intermediate within the reaction course. 3,5,7 Information on the kinetic description of the oxidative polymerization of aniline is limited in the literature, as the reaction is heterogeneous and a self-acceleration effect takes place during the polymerization phase. 5,8…”

Section: Introductionmentioning

confidence: 99%

“…3,5,7 Information on the kinetic description of the oxidative polymerization of aniline is limited in the literature, as the reaction is heterogeneous and a self-acceleration effect takes place during the polymerization phase. 5,8…”

Section: Introductionmentioning

confidence: 99%

“…In the later stage, peroxydisulfate anions oxidize growing PANI chains to the pernigraniline oxidation state and anilinium cations are oxidized by protonated diamino quinonoid units of pernigraniline to the anilinium cation radicals which are connected to the growing PANI chains, that is, the oxidant oxidizes the growing polymer and the molecules of the monomer are oxidized by the polymer. 3,5 The information on the termination of PANI chain growth is limited. It has been suggested that the hydrolysis of the terminal amino group in a growing PANI chain to a quinone prevents further addition of aniline because of which the chain growth terminates.…”

Section: Introductionmentioning

confidence: 99%

“…Chemical oxidation of aniline to p -benzoquinone is an alternative reaction 5,6,9,13 (Scheme 2) to the oxidative polymerization of aniline, which was used even in the industrial production of p -benzoquinone. According to the electrochemical studies of aniline oxidation, it is expected that p -benzoquinone is a product of hydrolysis of an oxidized aniline dimer, N -phenyl-1,4-benzoquinonediimine.…”

Section: Introductionmentioning

confidence: 99%

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Role of p-Benzoquinone in the Synthesis of a Conducting Polymer, Polyaniline

et al. 2019

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Polyaniline (PANI) and 2,5-dianilino- p -benzoquinone both are formed by oxidation of aniline in an acidic aqueous environment. The aim of this study is to understand the impact of addition of p -benzoquinone on the structure of PANI prepared by the oxidation of aniline hydrochloride with ammonium peroxydisulfate and to elucidate the formation of low-molecular-weight byproducts. An increasing yield and size-exclusion chromatography, Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy, and nuclear magnetic resonance analyses of the products show that p -benzoquinone does not act as a terminating agent in the synthesis of PANI and the content of 2,5-dianilino- p -benzoquinone increases with the increasing molar concentration of p -benzoquinone in the reaction mixture, [BzQ]. Regarding the structure of PANI, Raman and UV–visible spectra show that the doping level and the charge delocalization both decrease with the increase of [BzQ], and the FTIR spectra of the PANI bases indicate an increased concentration of benzenoid units at higher [BzQ]. We explain these observations by an increasing concentration of structural defects in PANI chains and propose a 2,5-dianilino- p -benzoquinone-like structure of these defects present as pendant groups. The bands typical of 2,5-dianilino- p -benzoquinone-like moiety are observed even in the vibrational spectra of the sample prepared without addition of p -benzoquinone. This confirms in situ oxidation of aniline to p -benzoquinone within the course of the oxidation of aniline hydrochloride to PANI.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Role of p-Benzoquinone in the Synthesis of a Conducting Polymer, Polyaniline

et al. 2019

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The Influence of the Methylene Blue Dye on the Rate and the Mechanism of the Oxidative Polymerization of Aniline

Mezhuev,

Motyakin,

Vorobev

et al. 2024

Macro Chemistry & Physics

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It is shown that one‐electron oxidation of aniline with methylene blue is possible only at low temperatures under UV radiation. The kinetics of aniline polymerization under the action of ammonium persulfate in the presence of catalytic amounts of methylene blue is studied. Kinetic curves are obtained by EPR spectroscopy at various temperatures and concentrations of methylene blue. The catalytic action of the unassociated form of methylene blue and the deactivation of reactive complexes by the dye dimers are shown to compete. In the context of the obtained results the autocatalysis mechanism of oxidative polymerization is considered, which suggests the formation of complexes of aniline and polyaniline that are subject to subsequent rapid oxidation by the persulfate anion.This article is protected by copyright. All rights reserved

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