Study of the Morphology Exhibited by Linear Segmented Polyurethanes

Five series of segmented polyurethanes with different hard segment content were prepared by the prepolymer mixing method. The nano‐morphology of the obtained polyurethanes and their microphase separation were investigated by infrared spectroscopy (FTIR), modulated differential scanning calorimetry (MDSC) and small‐angle X‐ray scattering (SAXS). Although highly hydrogen bonded segments were formed, high hard segment contents led to the presence of elevated degree of phase mixture and reduced the chain mobility, decreasing the hard domain precipitation and the soft segment crystallization. The applied techniques were able to show that the hard‐segment content and the hard‐segment interactions were the two controlling factors for determining the structure of segmented polyurethanes.