SULFOBETAINE POLYURETHANE IONOMERS .3. DIELECTRIC AND MECHANICAL-PROPERTIES OF POLYESTER POLYURETHANE IONOMER FILMS AND RELATED-COMPOUNDS WITH PB2+ AND CO2+

Tensile and dielectric relaxation properties of sulfobetaine polyureth ane, ionomers based on polyesters were studied comparatively to the no n-ionic polyurethane and derived compounds with pb2+ and Co2+, using s tress-strain and thermally stimulated depolarization currents (TSDC) m ethods. Introduction of ionic centers into polyurethane chain improves the tensile properties and modifies the TSDC spectra. These effects a re assigned to an enhancement of the microphase segregation. Complexat ion with Pb2+ and Co2+ diminishes the tensile properties, suggesting t hat an increase of phase mixing occurs determined by a partial neutral ization of ionic centers. Treatment with H2S slightly increases tensil e properties and changes TSDC spectra owing to the presence of the sem iconducting microphases formed by clustering of the metal sulfides PbS and CoS, respectively.