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

The relationships between structure and morphology on the one hand and mole cular 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 sca nning calorimetry (DSC), small-angle X-ray scattering, water sorption and d iffusion measurements, thermally stimulated depolarization currents (TSDC) techniques and broadband (10(-2) to 10(9) Hz) dielectric relaxation spectro scopy (DRS). These systems may be considered as models for the investigatio n of single ionic (anionic) conductivity. The various techniques employed p rovided several indications that the degree of microphase separation into h ard-segment microdomains and soft-segment microphase is higher in the syste m with Ni than with Cu ions. The relationships between DSC, TSDC and DRS, w ith respect to characteristic time scales, were investigated on the basis o f Arrhenius plot for the cc relaxation associated with the glass transition of soft-segment microphase. Conductivity effects were studied within the f ormalisms of complex permittivity and complex electric modulus. (C) 2000 El sevier Science Ltd. All rights reserved.