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

Polyester-based polyurethanes were synthesized from 4,4'-methylenebis-(phen yl isocyanate) (MDI) with butanediol as a chain extender and low molecular weight polyester-diol as a soft segment. Two polyesters were used in the sy nthesis of polyurethanes. One of the polyesters was synthesized from adipic acid and 1,6-hexanediol, which had an even number of carbon atoms. The oth er polyester was synthesized from pimelic acid and 1,5-pentanediol, which h ad an odd number of carbon atoms. The effect of even carbon monomers and od d carbon monomers of polyester soft segments on the phase segregation of so ft 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.