✦ LIBER ✦

Ultrasonic and dielectric studies of segmented ester polyurethanes

✍ Scribed by C. Delides; R.A. Pethrick

Publisher: Elsevier Science
Year: 1981
Tongue: English
Weight: 472 KB
Volume: 17
Category: Article
ISSN: 0014-3057
DOI: 10.1016/0014-3057(81)90108-7

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✦ Synopsis

Ultrasonic and dielectric relaxation measurements are reported as a function of frequency and temperature for a series of segmented ester polyurethanes. Glass transitions for the ester block were determined using a combination of differential scanning calorimetry and dilatometry. The activation energy associated with the dipolar relaxation of the ester group was found to be sensitive to changes in the molecular weight and the relative proportions of the ester and isocyanate in the polymers. These data are discussed with reference to the morphological changes which are known to occur in these systems.

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