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Solution properties of a hydrophobically modified polymer

Thuresson, Krister LU (1996)
Abstract
The influence of hydrophobic modification on solution properties of water-soluble polymers in the semi-dilute regime have been studied. The nonionic ethyl(hydroxyethyl)cellulose (EHEC) and its hydrophobically modified analogue (HM-EHEC) are used as model substances. Interactions between the polymer molecules in solution and a third component are investigated, and in particular the influence of the surfactant sodium dodecylsulfate (SDS). The polymer/SDS complex formation is investigated by using several techniques (phase behaviour, rheology, calorimetry, DS- sensitive electrode, NMR, and light scattering and fluorescence techniques). This combination of methods gives thermodynamic information on the complex formation, as well as information... (More)
The influence of hydrophobic modification on solution properties of water-soluble polymers in the semi-dilute regime have been studied. The nonionic ethyl(hydroxyethyl)cellulose (EHEC) and its hydrophobically modified analogue (HM-EHEC) are used as model substances. Interactions between the polymer molecules in solution and a third component are investigated, and in particular the influence of the surfactant sodium dodecylsulfate (SDS). The polymer/SDS complex formation is investigated by using several techniques (phase behaviour, rheology, calorimetry, DS- sensitive electrode, NMR, and light scattering and fluorescence techniques). This combination of methods gives thermodynamic information on the complex formation, as well as information about the dynamics of the polymer/surfactant complex. In a binary, semi-dilute, HM-EHEC solution the hydrophobic tails associate in clusters with an average of ten tails. These 'pre-formed' micelles act as nucleation sites for other molecules that contain hydrophobic moieties. The number of mixed micelles, and the strengths of the inter polymeric bonds which they give rise to, control both microscopic properties (as chain motions) and macroscopic behaviour (as rheology and phase behaviour). Experimental phase studies with hexanol as a third component were compared with model calculations in a modified Flory-Huggins approach. By assuming that hydrophobic modification causes enhanced association with the polymer semi-quantitative agreement was found. The associative phase separation that is usually observed in mixtures of two oppositely charged polyelectrolytes is effectively prevented by hydrophobic modification of both polyelectrolytes; a highly viscous phase is formed. (Less)
Please use this url to cite or link to this publication:
author
opponent
  • Leibler, Ludwik, Elf-Atochem, UMR CAL, 95 rue Danton, B. P. 108, 92303 Levallois-Perret cedex, France
organization
publishing date
type
Thesis
publication status
published
subject
keywords
sodium dodecylsulfate, surfactants, fluorescence, light scattering, NMR, rheology, cloud point, phase behaviour, polyelectrolytes, ethyl(hydroxyethyl)cellulose, hydrophobically modified, water soluble polymers, aggregation number, association, Physical chemistry, Fysikalisk kemi
pages
35 pages
publisher
Physical Chemistry 1, Lund University
defense location
lecture hall C, Chemical Center, Lund
defense date
1996-05-25 10:15
external identifiers
  • Other:ISRN: LUNKDL/NKKF--96/1027--SE
ISBN
ISBN91-628-2088-5
language
English
LU publication?
yes
id
274b67bb-cd1e-46cc-b763-3f2b70b7bb30 (old id 28391)
date added to LUP
2007-06-11 14:24:05
date last changed
2016-09-19 08:45:15
@misc{274b67bb-cd1e-46cc-b763-3f2b70b7bb30,
  abstract     = {The influence of hydrophobic modification on solution properties of water-soluble polymers in the semi-dilute regime have been studied. The nonionic ethyl(hydroxyethyl)cellulose (EHEC) and its hydrophobically modified analogue (HM-EHEC) are used as model substances. Interactions between the polymer molecules in solution and a third component are investigated, and in particular the influence of the surfactant sodium dodecylsulfate (SDS). The polymer/SDS complex formation is investigated by using several techniques (phase behaviour, rheology, calorimetry, DS- sensitive electrode, NMR, and light scattering and fluorescence techniques). This combination of methods gives thermodynamic information on the complex formation, as well as information about the dynamics of the polymer/surfactant complex. In a binary, semi-dilute, HM-EHEC solution the hydrophobic tails associate in clusters with an average of ten tails. These 'pre-formed' micelles act as nucleation sites for other molecules that contain hydrophobic moieties. The number of mixed micelles, and the strengths of the inter polymeric bonds which they give rise to, control both microscopic properties (as chain motions) and macroscopic behaviour (as rheology and phase behaviour). Experimental phase studies with hexanol as a third component were compared with model calculations in a modified Flory-Huggins approach. By assuming that hydrophobic modification causes enhanced association with the polymer semi-quantitative agreement was found. The associative phase separation that is usually observed in mixtures of two oppositely charged polyelectrolytes is effectively prevented by hydrophobic modification of both polyelectrolytes; a highly viscous phase is formed.},
  author       = {Thuresson, Krister},
  isbn         = {ISBN91-628-2088-5},
  keyword      = {sodium dodecylsulfate,surfactants,fluorescence,light scattering,NMR,rheology,cloud point,phase behaviour,polyelectrolytes,ethyl(hydroxyethyl)cellulose,hydrophobically modified,water soluble polymers,aggregation number,association,Physical chemistry,Fysikalisk kemi},
  language     = {eng},
  pages        = {35},
  publisher    = {ARRAY(0x9ad6518)},
  title        = {Solution properties of a hydrophobically modified polymer},
  year         = {1996},
}