Title :
Dielectric properties of polyurethane elastomers
Author :
Apekis, L. ; Pissis, P. ; Christodoulides, C. ; Schlosser, E. ; Schonhals, A. ; Carius, H.E.
Author_Institution :
Dept. of Phys., Nat. Tech. Univ. of Athens, Greece
Abstract :
The dielectric behavior of polyester-urethane elastomers and the effects associated with chemical and physical crosslinking in these polymers were studied by the thermally stimulated depolarization current (TSDC) method in the temperature range of 77-300 K, and by the AC method in the frequency range of 10 Hz to 100 kHz at different temperatures around Tg. TSDC measurements show four dielectric relaxation mechanisms. A dipolar relaxation, which is due to molecular mobility of soft polyester parts at the glass transition of the copolymers, appears at temperatures between 231 and 238 K, depending on the density of chemical crosslinks. These results are discussed in comparison with those obtained by the AC method
Keywords :
dielectric relaxation; glass transition (polymers); polymers; thermally stimulated currents; 10 to 100000 Hz; 77 to 300 K; AC method; TSDC measurements; chemical crosslinking; chemical crosslinks; dielectric behavior; dielectric relaxation mechanisms; dipolar relaxation; glass transition; molecular mobility; physical crosslinking; polyester-urethane elastomers; polyurethane elastomers; soft polyester parts; thermally stimulated depolarization current; Chemicals; Dielectric measurements; Frequency; Glass; Mechanical factors; Permittivity; Physics; Polymers; Temperature dependence; Temperature distribution;
Conference_Titel :
Electrets, 1991. (ISE 7) Proceedings., 7th International Symposium on (Cat. No.91CH3029-6)
Conference_Location :
Berlin
Print_ISBN :
0-7803-0112-9
DOI :
10.1109/ISE.1991.167289
