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In situ determination of aniline polymerization kinetics through near‐infrared spectroscopy
Author(s) -
de Souza Fernando Gomes,
Anzai Thiago Koichi,
Rodrigues Marcus V. A.,
Melo Príamo Albuquerque,
Nele Márcio,
Pinto José Carlos
Publication year - 2008
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.29355
Subject(s) - aniline , dodecylbenzene , overtone , polymerization , monomer , chemistry , sulfonic acid , reaction rate constant , kinetic energy , polymer chemistry , photochemistry , kinetics , analytical chemistry (journal) , polymer , sulfonate , organic chemistry , spectral line , physics , sodium , quantum mechanics , astronomy
This article describes a method for the determination of kinetic constants in aniline polymerizations performed in the presence of dodecylbenzene sulfonic acid. The procedure was based on the measurement of light absorbances at 668 and 1026 nm. The absorption at 668 nm is related to pernigraniline formation and is ordinarily used for ultraviolet–visible kinetic studies. The absorption at 1026 nm is related to the second overtone of the NH bonds, which may be used to monitor the aniline consumption along the reaction time. Tzou and Gregory's empirical reaction model was used as a reference for kinetic studies. The best fits were obtained when the kinetic constants were evaluated at 1026 nm because of the lower noise/signal ratio in this spectral region and the smaller sensitivity to the pernigraniline/emeraldine transition during the last stages of the polymerization. The remarkable innovation supplied by this study is the possibility to study aniline polymerizations in situ in realistic reaction conditions, which will allow the use of concentrated monomer solutions, large reaction volumes, efficient cooling conditions, and agitation. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009