Structure-property relationships in segmented polyurethanes with metal chelates in the main chain

The relationships between structure and morphology on the one hand and molecular mobility on the other hand in segmented polyurethanes (SPU) based on oligo-oxytetramethylene glycol with metal ions (Cu, Ni) incorporated in the chains (SPU metal chelates) were investigated by means of differential scanning calorimetry (DSC), small-angle X-ray scattering, water sorption and diffusion measurements, thermally stimulated depolarization currents (TSDC) techniques and broadband (10(-2) to 10(9) Hz) dielectric relaxation spectroscopy (DRS). These systems may be considered as models for the investigation of single ionic (anionic) conductivity. The various techniques employed provided several indications that the degree of microphase separation into hard-segment microdomains and soft-segment microphase is higher in the system with Ni than with Cu ions. The relationships between DSC, TSDC and DRS, with respect to characteristic time scales, were investigated on the basis of Arrhenius plot for the cc relaxation associated with the glass transition of soft-segment microphase. Conductivity effects were studied within the formalisms of complex permittivity and complex electric modulus. (C) 2000 Elsevier Science Ltd. All rights reserved.