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The influence of tungsten compounds on the synthesis and properties of polyaniline
Author(s) -
Stejskal Jaroslav,
Trchová Miroslava,
Holler Petr,
Sapurina Irina,
Prokeš Jan
Publication year - 2005
Publication title -
polymer international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.592
H-Index - 105
eISSN - 1097-0126
pISSN - 0959-8103
DOI - 10.1002/pi.1888
Subject(s) - induction period , tungstate , polyaniline , sodium tungstate , inorganic chemistry , polymerization , tungsten , aniline , chemistry , sodium molybdate , nuclear chemistry , aqueous solution , molybdate , organic chemistry , polymer , catalysis
Aniline was oxidized in an acidic aqueous medium with ammonium peroxydisulfate in the presence of various concentrations of tungsten compounds. The oxidation has two phases: an induction period followed by the exothermic polymerization. The course of oxidation was monitored by recording the reaction temperature or pH. The introduction of 2 mol% sodium tungstate (relative to aniline) prolonged the induction period from 5 to 30 min. Such molar concentration of tungstosilicic acid delayed the onset of polymerization by 120 min. The effect of sodium molybdate was less pronounced; sodium chromate had no influence on the course of oxidation. The presence of tungsten compounds had not affected the conductivity and molecular weight of the produced polyaniline. FTIR spectra and density determinations have proved that tungstate and tungstosilicate counter‐ions have been incorporated into polyaniline when they were present in the reaction mixture. Copyright © 2005 Society of Chemical Industry