Synthesis and properties of polyoxyethylated amine polyurethane ionomers

Based on polyoxyethylated amines (M_n = 600, 1,200) derived from n-butyl amine and ethylene oxide, 4,4′-diphenylmethane diisocyanate, and different chain extenders, two series of polyether–polyurethane (PU) ionomers with reasonable mechanical properties were synthesized. Chain-extended by 1,4-butanediol and subsequently reacted with 1,3-propane sultone, PU elastomers can be conveniently converted to PU zwitterionomers whose ions are located in polyether soft segments. Chain-extended by N-methyl diethanolamine or sodium-S-1,2-dihydroxypropyl sulfonate along with ionization by 1,3-propane sultone, PU ionomers with ions incorporated into both hard and soft domains can be prepared. Physical properties were studied by means of Fourier transform infrared spectra, differential scanning calorimetry, and uniaxial stress–strain testing. Complex impedance spectra were also measured to estimate solid-state ionic conductivity. The results show that ionization of both hard and soft segments induced a much decreased glass transition temperature and brought higher ionic conductivity at room temperature. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67:2179–2185, 1998