8. Role of Chain Symmetry and Hydrogen Bonding in Segmented Polyurethane and Polyurea Copolymers with Monodisperse Hard Segments

8.1 CHAPTER SUMMARY Segmented polyurethane and polyurea copolymers whose hard segments are based on only a single diisocyanate molecule are thermoplastic; they can exhibit useful structural properties if the level of symmetry and/or cohesiveness of the hard microdomains is carefully selected. These parameters control the hard segments’ ability to establish long-range connectivity and percolation of the hard phase through the soft matrix. The development of a microphase morphology in these copolymers, following melt processing, is a time-dependent phenomenon that can be followed by tapping-mode atomic force microscopy.