Synthesis and electrochemical properties of redox active polyurethanes with ferrocene units in polyether soft segments

Electrochemical active segmented polyurethane with ferrocene units in polye ther soft segments (PU-S-Fc) has been originally synthesized and identified by H-1-NMR spectra. Electrochemical behaviors of PU-S-Fc blending with lit hium perchlorates were investigated by cyclic voltammetry. In N,N'-dimethyl formide solution, PU-S-Fc exhibited normal cathodic and anodic peaks of th e ferrocene/ferricinium (Fc/Fc(+)) couple. Compared with that of ferrocene molecules blended in ordinary polyurethane (PU-B-Fc), redox peaks of ferroc ene units in PU-S-Fc were found to be broader, which may be ascribed to the weak adsorption of the polyurethane on the electrode surface. The influenc e of lithium perchlorate concentration on peak potentials indicated that su pporting electrolytes played an important role in electrochemical redox of PU-S-Fc. In the solid state, PU-S-Fc/Li+ showed discernible redox peaks at temperatures higher than 60 degrees C, and an exponential increase curve of electrochemical response with an increase of temperature was found. Temper ature variations of the solid-state ionic conductivity for PU-S-Fc/Li+ can be interpreted by the Arrhenius equation. The similarity between the temper ature dependence of ionic conductivity and electrochemical response reveale d that transport mechanism of ionic and redox species in the polyurethane m atrix was controlled by the mobility of polyether chains. (C) 1999 John Wil ey & Sons, Inc.