Molecular mobility and protonic conductivity in polymers: hydrogels and ionomers

• Published in: Solid state ionics Vol. 125; no. 1-4; pp. 203 - 212
• Main Authors: Pissis, P, Kyritsis, A, Shilov, V.V
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01-10-1999; Elsevier Science
• Subjects: Applied sciences; Electrical, magnetic and optical properties; Exact sciences and technology; Fragility; Hydrogels; Ionic aggregation; Ionomers; Microphase separation; Organic polymers; Physicochemistry of polymers; Properties and characterization; Microphase separation; Ionic aggregation; Hydrogels; Poly(ethylene oxide); Ionomers; Polyurethanes; Fragility; Ionomer; Ionic cluster; Electrical properties; Segmented polymer; Experimental study; Dielectric relaxation; Thermostimulated depolarization; Ethylene oxide polymer; Colloidal gel; Supramolecular structure; Proton conductivity; Property structure relationship; Acid copolymer; Etherurethane polymer
• ISSN: 0167-2738; 1872-7689
• DOI: 10.1016/S0167-2738(99)00177-0

Dielectric relaxation spectroscopy (DRS) in wide ranges of frequency (10−2–1010 Hz) and temperature (170–350 K) and thermally stimulated depolarization currents (TSDC) techniques (77–300 K) were employed to study protonic conductivity and molecular mobility in poly(ethylene oxide) (PEO) hydrogels and in novel segmented polyurethane ionomers. High protonic DC conductivity values are obtained with both systems. In the hydrogels the results are discussed in terms of polymer–water interactions, and of temperature- and water-induced effects. In the ionomers additional information on microphase separation and ionic aggregation obtained by means of DSC, WAXS, SAXS and DMTA measurements provides a basis for discussing structure–property relationships in this class of materials. Proton conductivity in both systems is governed by the motion of the polymeric chains. In the ionomers DC conductivity increases with decreasing hard segment content, suggesting that proton motion occurs through the soft segments phase.