Title :
Dielectric properties of polyurethane block copolymers
Author :
Apekis, L. ; Pissis, P. ; Christodoulides, C. ; Spathis, G. ; Kontou, E. ; Kefalas, V.
Author_Institution :
Nat. Tech. Univ. of Athens, Greece
Abstract :
The dielectric behavior of polyurethane block copolymers with various molecular weights and amounts of soft and hard block segments was studied by the thermally stimulated depolarization current (TSDC) method, in the temperature range of 77-370 K. TSDC measurements show a double low-temperature dispersion attributed to γ and β relaxations and a peak at about 240 K, probably due to the glass transition of the amorphous soft phase of the copolymer. A peak also appears between 255 and 270 K, which is related to MWS-type polarization, occurring mainly in the amorphous soft phase
Keywords :
glass transition (polymers); polymer blends; polymer structure; thermally stimulated currents; 77 to 300 K; amorphous soft phase; glass transition; molecular weights; polyurethane block copolymers; thermally stimulated depolarization current; Amorphous materials; Dielectric losses; Dielectric measurements; Dispersion; Ducts; Glass; Phase measurement; Physics; Polarization; Temperature distribution;
Conference_Titel :
Electrets, 1988. (ISE 6) Proceedings., 6th International Symposium on (IEEE Cat. No.88CH2593-2)
Conference_Location :
Oxford
DOI :
10.1109/ISE.1988.38564
