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Polyaniline prepared in the presence of various acids: a conductivity study
Author(s) -
Stejskal Jaroslav,
Hlavatá Drahomíra,
Holler Petr,
Trchová Miroslava,
Prokeš Jan,
Sapurina Irina
Publication year - 2004
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.1406
Subject(s) - polyaniline , protonation , conductivity , crystallinity , aniline , polymerization , sulfuric acid , polymer chemistry , conductive polymer , organic base , materials science , chemistry , inorganic chemistry , organic chemistry , polymer , ion , composite material
Polyaniline (PANI) was prepared by the oxidation of aniline in the presence of various inorganic and organic acids at 20 °C and −50 °C. When strong acids were used, the conductivity of the protonated PANI was typically 1–10 S cm −1 . The results indicate that the protonation of PANI in media containing carboxylic acids was achieved with the help of sulfuric acid produced during the reaction with ammonium peroxydisulfate. The conductivity of PANI prepared under such conditions was reduced. Partial benzene‐ring sulfonation has been proposed to explain the wide range in conductivity of PANI bases, 10 −11 –10 −7 S cm −1 . The densities of the samples reflect the nature of the acid used. The densities of the corresponding PANI bases exhibit much less variation. Molecular weight and degree of crystallinity of PANI are higher when the polymerization is carried out at −50 °C. The conductivity of the PANI is determined mainly by way of protonation. The effects of molecular weight and of crystallinity on PANI conductivity are marginal. Copyright © 2004 Society of Chemical Industry