ISSN:
0021-8995
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
The viscoelastic properties of dilute aqueous solutions of methylcellulose at ultrasonic frequencies were investigated by a torsional method using quartz crystal resonators. The concentration dependences of G′ and G″ - ωηs increased with increasing temperature at 13 kHz, but at higher frequencies G′ and G″ - ωηs were simply proportional to the concentration irrespective of temperature. These results may be explained by the difference of corresponding viscoelastic mechanism at measuring frequencies. In order to examine the configuration of methylcellulose in water, which changes remarkably with temperature, the intrinsic values at various temperatures were experimentally obtained by extrapolation to zero concentration, and the frequency dependence of intrinsic dynamic viscosity was examined. The values of components of the complex intrinsic viscosity at various temperatures and their frequency dependences were quantitatively compared with those calculated from the Tschoegl theory. The values of hydrodynamic strength parameter in the Tschoegl theory for an aqueous solution of methylcellulose increased with increasing temperature, and an effect of the internal viscosity due to the aggregation of methylcellulose was observed at higher temperatures. However, on the whole, the viscoelastic behavior was relatively close to Rouse-like behavior.
Additional Material:
15 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/app.1974.070181113
