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Cyclodextrins in hydrophobically modified poly(ethylene glycol) solutions: Inhibition of polymer-polymer associations

Karlson, L; Thuresson, Krister LU and Lindman, Björn LU (2002) In Langmuir 18(23). p.9028-9034
Abstract
in an aqueous solution of a hydrophobically, end-modified poly(ethylene glycol) polymer, HM-PEG, the thickening effect is dependent on intermolecular hydrophobic associations and the formation of a network structure. In the present investigation cyclodextrin, CD, has been added to an aqueous HM-PEG solution and a decrease in Newtonian viscosity has been followed. The decreased viscosity refers to polymer-polymer associations becoming less numerous when complexes between polymer hydrophobic tails and CD become more frequent; CD-decorated polymer hydrophobic tails have no possibility of contributing to the network. It was found that deactivation of the first few hydrophobic tails has very large consequences for the viscosity. A termination... (More)
in an aqueous solution of a hydrophobically, end-modified poly(ethylene glycol) polymer, HM-PEG, the thickening effect is dependent on intermolecular hydrophobic associations and the formation of a network structure. In the present investigation cyclodextrin, CD, has been added to an aqueous HM-PEG solution and a decrease in Newtonian viscosity has been followed. The decreased viscosity refers to polymer-polymer associations becoming less numerous when complexes between polymer hydrophobic tails and CD become more frequent; CD-decorated polymer hydrophobic tails have no possibility of contributing to the network. It was found that deactivation of the first few hydrophobic tails has very large consequences for the viscosity. A termination of a fraction as small as 10% (or below) of the total amount of polymer hydrophobic tails may reduce viscosity to a level almost corresponding to that of the unmodified parent polymer. This can be understood by taking into account that a solution of a HM-PEG polymer is, expected to be inhomogeneous with large concentration fluctuations and that the viscosity is likely to be strongly decreased by reducing the probability of hydrophobic associations responsible for connecting different blusters. The effect of CD on rheology is very different for different architectures of hydrophobically modified polymer, in particular between graft copolymers and end-capped ones. This can be understood from the differences in network structure. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Langmuir
volume
18
issue
23
pages
9028 - 9034
publisher
The American Chemical Society
external identifiers
  • wos:000179087100045
  • scopus:0037069463
ISSN
0743-7463
DOI
10.1021/la026040t
language
English
LU publication?
yes
id
31a9a789-b481-48bc-b5d6-d87c3185ff8e (old id 324177)
date added to LUP
2007-10-29 14:35:05
date last changed
2017-02-12 03:26:46
@article{31a9a789-b481-48bc-b5d6-d87c3185ff8e,
  abstract     = {in an aqueous solution of a hydrophobically, end-modified poly(ethylene glycol) polymer, HM-PEG, the thickening effect is dependent on intermolecular hydrophobic associations and the formation of a network structure. In the present investigation cyclodextrin, CD, has been added to an aqueous HM-PEG solution and a decrease in Newtonian viscosity has been followed. The decreased viscosity refers to polymer-polymer associations becoming less numerous when complexes between polymer hydrophobic tails and CD become more frequent; CD-decorated polymer hydrophobic tails have no possibility of contributing to the network. It was found that deactivation of the first few hydrophobic tails has very large consequences for the viscosity. A termination of a fraction as small as 10% (or below) of the total amount of polymer hydrophobic tails may reduce viscosity to a level almost corresponding to that of the unmodified parent polymer. This can be understood by taking into account that a solution of a HM-PEG polymer is, expected to be inhomogeneous with large concentration fluctuations and that the viscosity is likely to be strongly decreased by reducing the probability of hydrophobic associations responsible for connecting different blusters. The effect of CD on rheology is very different for different architectures of hydrophobically modified polymer, in particular between graft copolymers and end-capped ones. This can be understood from the differences in network structure.},
  author       = {Karlson, L and Thuresson, Krister and Lindman, Björn},
  issn         = {0743-7463},
  language     = {eng},
  number       = {23},
  pages        = {9028--9034},
  publisher    = {The American Chemical Society},
  series       = {Langmuir},
  title        = {Cyclodextrins in hydrophobically modified poly(ethylene glycol) solutions: Inhibition of polymer-polymer associations},
  url          = {http://dx.doi.org/10.1021/la026040t},
  volume       = {18},
  year         = {2002},
}