Journal of Polymer Science Part B: Polymer Physics, Vol.35, No.10, 1545-1560, 1997
Dielectric Studies of Polymer-Water Interactions and Water Organization in Peo/Water Systems
We report the results of detailed investigations of polymer-water interactions and of the organization of water in the poly( ethylene oxide) (PEO)/water system by dielectric techniques. They include thermally stimulated depolarization currents (TSDC) techniques in the temperature range of 77-300 K and broadband dielectric relaxation spectroscopy (DRS) techniques of frequencies, 5 Hz-10 GHz, and temperatures, 173-300 K. The water content h was varied between 0 and 1.21 (grams of water per gram of dry PEO). The secondary gamma mechanism of PEO and the reorientation of absorbed water molecules were extensively studied. The gamma mechanism was found to be plasticized up to water contents of about 0.20. The reorientation of water molecules was studied in three different experiments and frequency/temperature regions. The results suggest strong interactions in the PEO/water system and indicate the presence of a separate water phase at high water contents.
Keywords:GLASS LIQUID TRANSITION;POLY(ETHYLENE OXIDE);ELECTRICAL RELAXATION;POLYETHYLENE OXIDE;DEPOLARIZATION THERMOCURRENT;POLY(PROPYLENE OXIDE);CRYSTALLINE POLYMERS;ELECTROLYTES;HYDROGELS;CONDUCTIVITY