Title :
Molecular mobility and hydration properties in polyurethane and styrene-acrylonitrile blends
Author :
Kanapitsas, A. ; Pissis, P.
Author_Institution :
Dept. of Phys., Nat. Tech. Univ. of Athens, Greece
Abstract :
Dielectric measurements by means of thermally stimulated depolarization currents (TSDC) techniques in the temperature range 90-300 K were used to study molecular mobility and morphology in blends of polyurethanes based on branched polymer polyol (PUR) and styrene-acrylonitrile copolymer (SAN) with different SAN content. Water sorption/desorption isotherms both in equilibrium (ESI) and dynamic (DSI) were used to measure isothermal water uptake and diffusion coefficients. Water sorption has a significant influence on the γ and β relaxations. With increasing water content the MWS peak shifts to lower temperatures. For all samples studied the amount of water at saturation was found to decrease with increasing temperature and SAN content in the blends
Keywords :
desorption; dielectric relaxation; diffusion; polymer blends; thermally stimulated currents; β relaxation; γ relaxation; 90 to 300 K; branched polymer polyol; diffusion coefficient; hydration; isothermal water uptake; molecular mobility; morphology; polyurethane; sorption/desorption isotherms; styrene-acrylonitrile blends; thermally stimulated depolarization currents; water content; Current measurement; Dielectric measurements; Morphology; Physics; Polarization; Polymers; Storage area networks; Temperature distribution; Temperature measurement; Water;
Conference_Titel :
Electrets, 1999. ISE 10. Proceedings. 10th International Symposium on
Conference_Location :
Athens
Print_ISBN :
0-7803-5025-1
DOI :
10.1109/ISE.1999.832090
