A Comparison of Hydrogen Bonding and Order in a Polyurethane and Poly(urethane−urea) and Their Blends with Poly(ethylene glycol)

TLDR: In this paper, Fourier transform infrared spectroscopy was used to characterize the distribution of hydrogen bonds in polyurethane and polyurea and their blends with poly(ethylene glycol) was examined.

Abstract: The effect of hydrogen bonding on the phase behavior of a chemically similar polyurethane and polyurea and their blends with poly(ethylene glycol) is examined. The polyurethane and polyurea were synthesized from the same diisocyanate, 1,5-diisocyanato-2-methylpentane, using an aromatic diol and aromatic diamine, respectively. Fourier transform infrared spectroscopy was used to characterize the distribution of hydrogen bonds in these polymers and their blends. The distribution of hydrogen bonds in the polyurethane homopolymer was found to be quite similar to that found in an amorphous polyurethane studied previously in this laboratory. However, upon annealing, some sort of ordered structure was detected spectroscopically. The polyurea formed an equivalent ordered structure much more readily at room temperature. Ordered hydrogen-bonded domains were also detected in the spectra of the blends, either after an extended time at room temperature or after annealing at an elevated temperature. The formation of ord...