Hydrophobically modified xanthan: an amphiphilic but not associative polymer.
Biomacromolecules
; 15(4): 1160-70, 2014 Apr 14.
Article
em En
| MEDLINE
| ID: mdl-24547905
ABSTRACT
Hydrophobic octyl moieties have been grafted in various densities onto the carboxylic acid functions of xanthan under its ordered conformation. The outcoming amphiphilic and associative properties were studied by fluorescence spectroscopy and rheology. Results showed that the conformation of xanthan is not affected by the chemical modification and remains the same as the native one. Additionally, xanthan derivatives do not show any viscoelastic enhancement; nevertheless, their dynamics is strongly slowed down the higher the grafting density, the slower the relaxation. We proved that hydrophobically modified xanthan, even being amphiphilic, does not exhibit any additional associating properties compared to the unmodified xanthan. The high stiffness of xanthan helices does not allow the derivatives to adopt the organization usually observed for flexible amphiphilic polymers. On the basis of these observations, a model depicting such a singular behavior is proposed.
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Base de dados:
MEDLINE
Assunto principal:
Polissacarídeos Bacterianos
Idioma:
En
Ano de publicação:
2014
Tipo de documento:
Article
País de afiliação:
França