G. Georgoussis et al., Structure-property relationships in segmented polyurethanes with metal chelates in the main chain, EUR POLYM J, 36(6), 2000, pp. 1113-1126
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.