Morphology and ionic conductivity of thermoplastic polyurethane electrolytes

Abstract

Thermoplastic polyurethane (TPU) with a mixture of soft segments [poly(ethylene glycol) (PEG) and poly(tetramethylene glycol) (PTMG)], denoted TPU-M, was prepared as an ion-conducting polymer electrolyte. TPUs with PEG and PTMG as soft segments were also synthesized individually as polymer electrolytes. The changes in the morphology and ion conductivity of the phase-segregated TPU-based polymer electrolytes as a function of the lithium perchlorate concentration were determined with differential scanning calorimetry, Fourier transform infrared spectroscopy, alternating-current impedance, and linear sweep voltammetry measurements. Both solid and gelatinous polymer electrolytes were characterized in this study. The effect of temperature on conductivity was studied. The conductivity changes revealed the combined influence of PTMG and PEG units in TPU-M. The swelling characteristics in a liquid electrolyte and the dimensional stability were evaluated for the three TPUs. Because of its dimensional stability and ionic conductivity, the TPU system containing both PEG and PTMG as soft segments was found to be more suitable for electrolyte applications. A room-temperature conductivity of approximately 1 ϫ 10 Ϫ4 was found for TPU-M containing 50 wt % liquid electrolyte.

Characterization of Novel Castor Oil-Based Polyurethane Polymer Electrolytes

“…[28]. According to Chen et al [29], the convoluted FTIR spectra in the C=O stretching region have three peaks due to free or non-hydrogen-bonded C=O (1727-1735 cm ) vibrations, respectively. The disordered hydrogen-bonded C=O corresponds to the hydrogen-bonding interactions with -NH groups in both amorphous and crystalline regions, whereas the ordered hydrogen-bonded C=O occurs within the crystalline hard domain of the PU [30].…”

Partial or Total Silylation of Polytetramethylene Glycol with Trimethylchlorosilane

“…As shown in the spectrum of unprotected TMSPTMG-g-HFP (PTMG-g-HFP) of Figure 3, the disappearance of all characteristic peaks for the Si-Me group and the recurrence of the hydroxyl characteristic peaks mean that the trimethylsilyl groups were successfully cleaved. 3 protons, is observed in spectrum of silylated PTMG, and furthermore, the signal corresponding to hydroxyl protons totally disappeared.…”

“…In this field, PTMG has replaced the classic polyesterdiols due to its good hydrolytic stability. Furthermore, PTMG is used as soft components in elastomers such as thermoplastic polyetheresters, thermoplastic polyetheramides, polyurethane fibers and crosslinked polyurethane elastomers (1)(2)(3)(4)(5).…”

Novel polymer electrolytes based on thermoplastic polyurethane and ionic liquid/lithium bis(trifluoromethanesulfonyl)imide/propylene carbonate salt system

“…The polymer acts as the medium to maintain the physical strength and shape of the electrolyte, and the percolated liquid medium (confined electrolyte) enables the transportation of lithium ions through the membrane [2]. Thermoplastic polyurethane (TPU) has been largely employed as polymeric matrix for the preparation of polymer electrolytes [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22]. Because of its excellent mechanical properties, TPU may provide an alternative to the widely used PVdF and its copolymers for the preparation of gel electrolytes.…”