Raman, infra-red and dsc studies of lithium coordination in a thermoplastic polyurethane

Fourier transform (FT)-Raman and infra-red (i.r.) spectroscopy were utilized to monitor changes in the morphology of a commercial, phase-segregated thermoplastic polyurethane (TPU) as a function of LiClO4 concentration (0.1 to 2.0 mmol/g TPU). Significant changes in both the FT-Raman and the FTi.r. spectra were detected which suggest a competition between hydrogen bonding and lithium cation coordination, especially between the hard segments of the host polymer matrix. A loss in long-range ordering of the hard domain was observed by differential scanning calorimetry with an increase in salt concentration. The ionic conductivity (sigma) was found to increase with increasing temperature and salt concentration. For the highest concentration used, sigma ranged from a very low value of similar to 1 x 10(-9) S cm(-1) at room temperature to similar to 1 x 10(-4) S cm(-1) at 130 degrees C.