ISSN:
0449-2978
Keywords:
Physics
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
The modified Birnboim transducer and a computerized data acquisition and processing system (DAPS) for the measurement of viscoelastic properties of macromolecular solutions are described. The apparatus has a continuous frequency range from 0.01 to ca. 700 Hz and a viscosity range from 2 to ca. 30,000 poise (sample volume 1 to 1.5 cm2). Sample temperature is controlled to within 0.002°C from -30°C to +80°C. Working displacements are 102 to 104 Å. The DAPS is designed for precise determinations of the magnitudes and relative phasing of two sinusoidally time-varying electrical signals (0.02%, 0.02°, respectively, for signals 〉 2 V peak) from 10-2 to 105 Hz. Cross-correlation techniques are used for noise rejection. For frequencies below 30 Hz values of the storage (G') and loss (G″) components of the complex shear modulus (G*) of 1 dyne/cm2 are determined to within 10% and 4%, respectively, for liquids of moderately low viscosity. Proportionately higher measurement accuracies for typical values of G' and G″ and the wide frequency and viscosity ranges permit extrapolation to infinite dilution and studies of limited molecular flexibility for many polymer - solvent systems.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1972.160100106
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