ISSN:
0025-116X
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
The dielectric and viscometric behaviour of poly(dibenzyl itaconate) (1) in 1,4-dioxane is studied as a function of temperature. The dipole moments at 25°C and at 33°C are determined by measuring the dielectric constant as a function of polymer concentration at fixed temperature. Also, the variation of the dielectric constant for a fixed concentration is determined at several temperatures in the temperature range between 15 and 39°C. The dipole moment is by 10% higher at 33°C than at 25°C, and the variation of the dielectric constant with temperature shows a stepwise increase between 25°C and 30°C. Viscosity measurements demonstrate an anomalous behaviour of 1 in 1, 4-dioxane at approximately the same range of temperatures. At ca. 25°C the value of the Huggins constant drops to practically zero. By measuring samples with different molecular weights the unperturbed dimensions, interaction parameter, and Mark-Houwink-Kuhn-Sakurada exponent are obtained. All of these parameters exhibit a discontinuity at ca. 25°C. The variations in the dielectric and viscometric behaviour with temperature are attributed to a conformational change of the macromolecules of 1 in 1, 4-dioxane.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/macp.1988.021890114
