Effect of polyester zigzag structure on the phase segregation of polyester-based polyurethanes

Polyester-based polyurethanes were synthesized from 4,4'-methylenebis-(phenyl isocyanate) (MDI) with butanediol as a chain extender and low molecular weight polyester-diol as a soft segment. Two polyesters were used in the synthesis of polyurethanes. One of the polyesters was synthesized from adipic acid and 1,6-hexanediol, which had an even number of carbon atoms. The other polyester was synthesized from pimelic acid and 1,5-pentanediol, which had an odd number of carbon atoms. The effect of even carbon monomers and odd carbon monomers of polyester soft segments on the phase segregation of soft and hard segments was studied by DSC (differential scanning calorimetry) and FTIR (Fourier transform infrared spectroscopy). (C) 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 2095-2104, 1999.