Journal of Applied Polymer Science, Vol.74, No.11, 2674-2680, 1999
Synthesis and electrochemical properties of redox active polyurethanes with ferrocene units in polyether soft segments
Electrochemical active segmented polyurethane with ferrocene units in polyether soft segments (PU-S-Fc) has been originally synthesized and identified by H-1-NMR spectra. Electrochemical behaviors of PU-S-Fc blending with lithium perchlorates were investigated by cyclic voltammetry. In N,N'-dimethyl formide solution, PU-S-Fc exhibited normal cathodic and anodic peaks of the ferrocene/ferricinium (Fc/Fc(+)) couple. Compared with that of ferrocene molecules blended in ordinary polyurethane (PU-B-Fc), redox peaks of ferrocene 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 influence of lithium perchlorate concentration on peak potentials indicated that supporting 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. Temperature variations of the solid-state ionic conductivity for PU-S-Fc/Li+ can be interpreted by the Arrhenius equation. The similarity between the temperature dependence of ionic conductivity and electrochemical response revealed that transport mechanism of ionic and redox species in the polyurethane matrix was controlled by the mobility of polyether chains.