DIELECTRIC STUDIES OF POLYMER-WATER INTERACTIONS AND WATER ORGANIZATION IN PEO WATER SYSTEMS/

We report the results of detailed investigations of polymer-water inte ractions and of the organization of water in the poly( ethylene oxide) (PEO)/water system by dielectric techniques. They include thermally s timulated depolarization currents (TSDC) techniques in the temperature range of 77-300 K and broadband dielectric relaxation spectroscopy (D RS) 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 p er gram of dry PEO). The secondary gamma mechanism of PEO and the reor ientation of absorbed water molecules were extensively studied. The ga mma mechanism was found to be plasticized up to water contents of abou t 0.20. The reorientation of water molecules was studied in three diff erent experiments and frequency/temperature regions. The results sugge st strong interactions in the PEO/water system and indicate the presen ce of a separate water phase at high water contents. (C) 1997 John Wil ey & Sons, Inc.