|
KMID : 1059519960400120748
|
|
Journal of the Korean Chemical Society
1996 Volume.40 No. 12 p.748 ~ p.755
|
|
|
Temperature Dependence of the Intrinsic Viscosities for Poly(ethylene oxide)-Water and -Aqueous Urea Systems
|
|
Jeon Sang-Il
Chang Gue-Dong
|
|
|
Abstract
|
|
|
|
The effects of temperature on the conformational properties of poly(ethylene oxide) (PEO) in aqueous and aqueous urea solutions are reported. The values of intrinsic viscosity and Huggins coefficients for the PEO dissolved in water and urea/water mixtures (urea concentration 0.2, 1, and 2 M) were obtained using a viscometry method and discussed with respect to the change of water structure. At low temperatures (below 22 ℃), the PEO-water interaction is favorable and the chain can be extended, whereas at higher temperatures (above 24 ℃), it is less favorable and the chain can be contracted by a hydrophobic hydration, i.e., the PEO-water interaction becomes to be unfavorable with the increase in temperature. As the urea is added to the system, the PEO chain can be more extended and huged by the perturbation of the structured water originating from the unfavorable PEO-water interaction. The effect of temperature on the intrinsic viscosity values shows an Arrhenius behavior. The activation energies of the viscous flow were obtained and discussed.
|
|
|
KEYWORD
|
|
|
|
|
|
FullTexts / Linksout information
|
|
|
|
|
|
Listed journal information
|
|
|