[Development of morphology and mechanical properties in polyurethane-urea(PUU) curing process].

The development of morphology and mechanical properties of PUU in bulk prepolymer polymerization process was investigated by TEM and in situ FTIR. The data from the FTIR spectra showed that the absorbance of NH band was becoming sharp and its band sites shifted to lower wavenumbers with the increase of reaction time, the absorbance of free urethance carbonyl kept nearly constant at low conversion, and then became weaker, and finally became little because of strong hydrogen bond affect of more and more new wrealink group at high conversion. With increasing of the reaction time, the band sites of urea carbonyl also shifted to the lower wavenumbers and at the same time, the absorbance of ordered urea carbonyl became sharper and sharper. The carbonyl bands vibration models available during curing process were further assigned. The photos of TEM showed that the domains of hard segments became clearer with buildup of hydrogen bond between urealinks.