Rheological behavior of hydrophobically modified hydroxyethyl cellulose solutions: A linear viscoelastic model

The rheological behavior of hydrophobically modified hydroxyethyl cellulose HMHEC, an associative thickener, was studied and compared with that of hydrophobically modified ethoxylated urethanes HEURs and nonassociative celluloses. In contrast to HEURs, a simple Maxwell model does not fit the linear...

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Autores: Maestro Garriga, Alicia, González, C., Gutiérrez González, José María, 1953-
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2002
País:España
Institución:Universidad de Barcelona
Repositorio:Dipòsit Digital de la UB
OAI Identifier:oai:diposit.ub.edu:2445/24847
Acceso en línea:https://hdl.handle.net/2445/24847
Access Level:acceso abierto
Palabra clave:Reologia
Cel·lulosa
Viscoelasticitat
Polímers
Solucions (Química)
Rheology
Cellulose
Viscoelasticity
Polymers
Solution (Chemistry)
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spelling Rheological behavior of hydrophobically modified hydroxyethyl cellulose solutions: A linear viscoelastic modelMaestro Garriga, AliciaGonzález, C.Gutiérrez González, José María, 1953-ReologiaCel·lulosaViscoelasticitatPolímersSolucions (Química)RheologyCelluloseViscoelasticityPolymersSolution (Chemistry)The rheological behavior of hydrophobically modified hydroxyethyl cellulose HMHEC, an associative thickener, was studied and compared with that of hydrophobically modified ethoxylated urethanes HEURs and nonassociative celluloses. In contrast to HEURs, a simple Maxwell model does not fit the linear viscoelastic behavior of HMHEC. Differences are attributed to the stiffness and comb structure of HMHEC. A generalized Maxwell model with a logarithmic distribution of relaxation times is proposed, and another parameter that includes Rouse-like relaxation is added to fit behavior at high frequencies. Four parameters are needed to describe HMHEC viscoelasticity: a mean relaxation time, lM ; its corresponding standard deviation, s; a plateau modulus, GN ; and a viscosity at infinite frequency, h ` . Satisfactory fitting is obtained for all concentrations and temperatures in the range of frequencies studied. The sharp increase of GN with concentration indicates loop-to-bridge transitions. Temperature does not influence GN , since the reduction in the number density of elastically effective chains caused by Brownian motion masks the direct effect of temperature. The dependence of lM on temperature follows the Arrhenius equation, as does the relaxation time of HEURs, but it does not change with concentration, presumably because the comb structure of HMHEC prevents the formation of long superchains.The Society of Rheology2002info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionapplication/pdfhttps://hdl.handle.net/2445/24847Articles publicats en revistes (Enginyeria Química i Química Analítica)reponame:Dipòsit Digital de la UBinstname:Universidad de BarcelonaInglésReproducció del document publicat a: http://dx.doi.org/10.1122/1.1427910Journal of Rheology, 2002, vol. 46, p. 127-143http://dx.doi.org/10.1122/1.1427910(c) The Society of Rheology, 2002info:eu-repo/semantics/openAccessoai:diposit.ub.edu:2445/248472026-05-27T06:46:51Z
dc.title.none.fl_str_mv Rheological behavior of hydrophobically modified hydroxyethyl cellulose solutions: A linear viscoelastic model
title Rheological behavior of hydrophobically modified hydroxyethyl cellulose solutions: A linear viscoelastic model
spellingShingle Rheological behavior of hydrophobically modified hydroxyethyl cellulose solutions: A linear viscoelastic model
Maestro Garriga, Alicia
Reologia
Cel·lulosa
Viscoelasticitat
Polímers
Solucions (Química)
Rheology
Cellulose
Viscoelasticity
Polymers
Solution (Chemistry)
title_short Rheological behavior of hydrophobically modified hydroxyethyl cellulose solutions: A linear viscoelastic model
title_full Rheological behavior of hydrophobically modified hydroxyethyl cellulose solutions: A linear viscoelastic model
title_fullStr Rheological behavior of hydrophobically modified hydroxyethyl cellulose solutions: A linear viscoelastic model
title_full_unstemmed Rheological behavior of hydrophobically modified hydroxyethyl cellulose solutions: A linear viscoelastic model
title_sort Rheological behavior of hydrophobically modified hydroxyethyl cellulose solutions: A linear viscoelastic model
dc.creator.none.fl_str_mv Maestro Garriga, Alicia
González, C.
Gutiérrez González, José María, 1953-
author Maestro Garriga, Alicia
author_facet Maestro Garriga, Alicia
González, C.
Gutiérrez González, José María, 1953-
author_role author
author2 González, C.
Gutiérrez González, José María, 1953-
author2_role author
author
dc.subject.none.fl_str_mv Reologia
Cel·lulosa
Viscoelasticitat
Polímers
Solucions (Química)
Rheology
Cellulose
Viscoelasticity
Polymers
Solution (Chemistry)
topic Reologia
Cel·lulosa
Viscoelasticitat
Polímers
Solucions (Química)
Rheology
Cellulose
Viscoelasticity
Polymers
Solution (Chemistry)
description The rheological behavior of hydrophobically modified hydroxyethyl cellulose HMHEC, an associative thickener, was studied and compared with that of hydrophobically modified ethoxylated urethanes HEURs and nonassociative celluloses. In contrast to HEURs, a simple Maxwell model does not fit the linear viscoelastic behavior of HMHEC. Differences are attributed to the stiffness and comb structure of HMHEC. A generalized Maxwell model with a logarithmic distribution of relaxation times is proposed, and another parameter that includes Rouse-like relaxation is added to fit behavior at high frequencies. Four parameters are needed to describe HMHEC viscoelasticity: a mean relaxation time, lM ; its corresponding standard deviation, s; a plateau modulus, GN ; and a viscosity at infinite frequency, h ` . Satisfactory fitting is obtained for all concentrations and temperatures in the range of frequencies studied. The sharp increase of GN with concentration indicates loop-to-bridge transitions. Temperature does not influence GN , since the reduction in the number density of elastically effective chains caused by Brownian motion masks the direct effect of temperature. The dependence of lM on temperature follows the Arrhenius equation, as does the relaxation time of HEURs, but it does not change with concentration, presumably because the comb structure of HMHEC prevents the formation of long superchains.
publishDate 2002
dc.date.none.fl_str_mv 2002
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv https://hdl.handle.net/2445/24847
url https://hdl.handle.net/2445/24847
dc.language.none.fl_str_mv Inglés
language_invalid_str_mv Inglés
dc.relation.none.fl_str_mv Reproducció del document publicat a: http://dx.doi.org/10.1122/1.1427910
Journal of Rheology, 2002, vol. 46, p. 127-143
http://dx.doi.org/10.1122/1.1427910
dc.rights.none.fl_str_mv (c) The Society of Rheology, 2002
info:eu-repo/semantics/openAccess
rights_invalid_str_mv (c) The Society of Rheology, 2002
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
dc.publisher.none.fl_str_mv The Society of Rheology
publisher.none.fl_str_mv The Society of Rheology
dc.source.none.fl_str_mv Articles publicats en revistes (Enginyeria Química i Química Analítica)
reponame:Dipòsit Digital de la UB
instname:Universidad de Barcelona
instname_str Universidad de Barcelona
reponame_str Dipòsit Digital de la UB
collection Dipòsit Digital de la UB
repository.name.fl_str_mv
repository.mail.fl_str_mv
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score 15,300724

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