화학공학소재연구정보센터
Electrochimica Acta, Vol.48, No.6, 669-677, 2003
The effect of EPIDA units on the conductivity of poly(ethylene glycol)-4,4'-diphenylmethane diisocyanate-EPIDA polyurethane electrolytes
Novel thermoplastic polyurethanes with chelating groups were synthesized from 4,4'-diphenylmethane diisocyanate (MDI), poly(ethylene glycol) (PEG), and EP-IDA. Differential scanning calorimetry (DSC), fourier transform infrared spectroscopy (FT-IR), and impedance spectroscopy (IS) were used to monitor changes in the morphology of these polyurethanes with the concentration of lithium perchlorate (LiClO4) dopants. Adding the salt significantly changes the FTIR spectrum of the polyurethane, indicating an interaction between the lithium cation within the urethane group and the chelating group. The soft segment T-g increases with LiClO4 concentration, as determined by DSC, indicating that solubility of the lithium cation in the host polyurethane increases with the chelating groups. IS shows that the bulk conductivity reaches a maximum as the salt concentration is increased. One of the investigated polyurethane electrolytes has an ionic conductivity as high as similar to 10(-6) S cm(-1) at room temperature.