Please use this identifier to cite or link to this item:
|Scopus||Web of Science®||Altmetric|
|Title:||Rheology control by modulating hydrophobic and inclusive associations of side-groups in poly (acrylic acid)|
|Citation:||Asia Pacific Journal of Chemical Engineering, 2009; 4(5 Sp Iss):537-543|
|Publisher:||John Wiley & Sons, Inc.|
|Jie Wang, Li Li, Hailan Ke, Peng Liu, Li Zheng, Xuhong Guo and Stephen F. Lincoln|
|Abstract:||In this article we demonstrated that the viscosities of modified poly (acrylic acid) (PAA) solutions were tunable by modulating the hydrophobic and inclusion association between alkyl groups and β-cyclodextrin (β-CD) groups grafted to PAA. The viscosity can be controlled by changing the host-guest molar ratio, alkyl chain length, polymer concentration, salt concentration, pH value, temperature, or addition of native β-CD. A viscosity maximum for inclusive polymer networks constructed by mixing hydrophobically modified PAA (HMPAA) and β-CD-modified PAA (β-CDPAA) appeared at the alkyl : β-CD molar ratio of 1 : 1, which implies the inclusion association between HM and β-CD grafts is binary. Longer side chain length or higher polymer concentration led to higher viscosity for aqueous HMPAA solution with only hydrophobic association or its mixture with β-CDPAA with inclusion association. Monotonically increasing the ionic strength or pH value resulted in a viscosity maximum due to the competition between electrostatic repulsion and hydrophobic or inclusive association. The hydrophobic interactions of alkyl groups could be masked by native β-CD, and the networks of HMPAA and β-CDPAA mixture deconstructed upon addition of native β-CD molecules. The storage modulus and loss modulus of hydrophobic HMPAA and inclusive HMPAA + β-CDPAA solutions obey time-temperature superposition. The horizontal and vertical temperature shift factors obeyed a simple-exponential Arrhenius relationship, where the activation energies for hydrophobic association system were found to be 3.4 and -12.1 kJ/mol, and for inclusive association system 53.9 and -2.9 kJ/mol, respectively. © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.|
|Description:||Copyright © 2010 Curtin University of Technology and John Wiley & Sons Ltd.|
|Appears in Collections:||Aurora harvest|
Environment Institute publications
Files in This Item:
There are no files associated with this item.
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.