Molecular mobility and protonic conductivity in polymers: hydrogels and ionomers

Dielectric relaxation spectroscopy (DRS) in wide ranges of frequency (10(-2 )-10(10) Hz) and temperature (170-350 K) and thermally stimulated depolariz ation currents (TSDC) techniques (77-300 K) were employed to study protonic conductivity and molecular mobility in poly(ethylene ride) (PEO) hydrogels and in novel segmented polyurethane ionomers. High protonic DC conductivit y values are obtained with both systems. In the hydrogels the results are d iscussed in terms of polymer-water interactions, and of temperature- and wa ter-induced effects. In the ionomers additional information on microphase s eparation and ionic aggregation obtained by means of DSC, WAXS, SAXS and DM TA measurements provides a basis for discussing structure-property relation ships in this class of materials. Proton conductivity in both systems is go verned by the motion of the polymeric chains. In the ionomers DC conductivi ty increases with decreasing hard segment content, suggesting that proton m otion occurs through the soft segments phase (C) 1999 Elsevier Science B.V. All rights reserved.