Three different segmented thermoplastic polyurethanes (TPUs) were synthesized with 4,4Ј-methylenebis(phenyl isocyanate) as a hard segment and poly(ethylene glycol) (PEG) or poly(propylene glycol) (PPG) or an equal mixture of PEG and PPG with molecular 2000 as soft segments. The soft-segment component of TPU was changed to monitor modifications in chemical and physical properties among the three TPUs. Differential scanning calorimetry (DSC) and thermogravimetric analysis were used to monitor changes in thermal characteristics. Fourier transform infrared spectroscopy (FTIR) was employed to predict the interaction between the lithium cation and the hard or soft segment in the presence of added LiClO 4 . The deconvolution results of spectral bands associated with the NOH groups of these TPUs were used to obtain such information. Impedance spectroscopy was used to inspect the changes in the bulk conductivity of these TPUs caused by alteration of the soft-segment component. The conductivity changes were explained through combined DSC and FTIR results. The electrochemical stability of the TPU systems was studied by linear sweep voltammetry. The results showed that the copolymer system had better thermal and electrochemical stability than the other systems.

Segmented thermoplastic polyurethane (TPU) was synthesized from methylene bis(cyclohexyl isocyanate) (H 12 MDI), ethylenediamine (EDA), and poly(propylene glycol) (PPG) with a molecular weight of 1000. The ratio of hard segment to soft segment (NCO/OH) is changed to test the chemical and physical properties. Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and impedance spectroscopy (IS) were utilized to monitor the phase change of these TPU samples with various lithium perchlorate (LiClO 4 ) concentrations. Significant changes occur in the FTIR spectrum of the TPU with LiClO 4 concentration above 0.5 mmol/g TPU, indicating that an interaction existed between the lithium cation and the hard segment or soft phase. The soft-segment T g increased with increasing LiClO 4 concentration through the examination of DSC. IS results indicate an increase in bulk conductivity as the salt concentration is increased. Electrochemical stability of the TPU sample was studied by cyclic votammetry (CV).