A Reinvestigation Of A Colorimetric Method Aimed At Quantifying Minute Amounts Of Carboxylic Acids Present In Polystyrene And Poly(n-alkyl Methacrylate)s

dc.creatorKerloc'h
dc.creatorBrendan; Brissault
dc.creatorBlandine; Penelle
dc.creatorJacques; Atvars
dc.creatorTeresa Dib Zambon
dc.date2017
dc.datejun
dc.date2017-11-13T11:32:11Z
dc.date2017-11-13T11:32:11Z
dc.date.accessioned2018-03-29T05:46:54Z
dc.date.available2018-03-29T05:46:54Z
dc.identifierJournal Of Applied Polymer Science. Wiley-blackwell, v. 134, p. , 2017.
dc.identifier0021-8995
dc.identifier1097-4628
dc.identifierWOS:000397614000027
dc.identifier10.1002/app.44931
dc.identifierhttp://onlinelibrary-wiley-com.ez88.periodicos.capes.gov.br/doi/10.1002/app.44931/full
dc.identifierhttp://repositorio.unicamp.br/jspui/handle/REPOSIP/326036
dc.identifier.urihttp://repositorioslatinoamericanos.uchile.cl/handle/2250/1363042
dc.descriptionA reinvestigation of a method (Christoff, M.; Yamaki, S. B.; de Oliveira, M. G.; Atvars, T. D. Z. J. Appl. Polym. Sci. 2004, 92, 830-838) aimed at quantitatively determining trace amounts of residual carboxylic acid functional groups in polymethacrylates and polystyrene has been carried out. The original technique was based on the monitoring of an absorption band in the UV-visible region (610 nm) that appears after known amounts of polymer are added to a benzene solution containing the basic form of the Nile Blue A dye. It is shown here that the assumption upon which the methodology is based, that is, the occurrence of a 1:1 stoichiometric and complete proton transfer of the carboxylic acid to the dye, is invalid and yields greatly underestimated values for the COOH contents, possibly by 2-3 orders of magnitude. In addition, temperature strongly influences the equilibrium constant for the acid-base reaction. Lastly, preparation and storage of the analytical solution was found to be problematic, supporting earlier claims that hydrolysis of Nile Blue A base does occur when preparing the benzene solution and/or over storage, yielding Nile Red dye whose absorption in the visible part of the spectrum significantly overlaps. Based on the above results, further use of this technique, at least in its quantitative version, should be discouraged. (c) 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44931.
dc.description134
dc.description23
dc.descriptionFrench Agence Nationale de la Recherche [ANR-14-CE16-0023-03]
dc.languageEnglish
dc.publisherWiley-Blackwell
dc.publisherHoboken
dc.relationJournal of Applied Polymer Science
dc.rightsfechado
dc.sourceWOS
dc.subjectAcid Content
dc.subjectColorimetric Titration
dc.subjectPolymer Analysis
dc.subjectPolymethacrylates
dc.subjectPolystyrene
dc.titleA Reinvestigation Of A Colorimetric Method Aimed At Quantifying Minute Amounts Of Carboxylic Acids Present In Polystyrene And Poly(n-alkyl Methacrylate)s
dc.typeArtículos de revistas


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