| Abstract: | Multiphase polymer systems with special phase structures and properties can be achieved by the proper design of the polymer constitution and the appropriate sample treatment. Multiblock copolymers consisting of molecularly uniform polyurethane segments of various molecularly engineered structures and connected by highly flexible polyether segments have been synthesized. The segregation of the hard segments and the size, shape and perfection of the hard domains can be controlled by the hard segment's architecture in that either extended chain crystallization or chain folding occurs. The same superstructure and properties as of the above multiblock copolymers can be mimicked by specially designed graft copolymers with polyether backbone and polyurethane branches, again uniform and molecularly engineered. This study has shown that the morphology and superstructure of macromolecular systems can be precisely controlled by the molecularly designed chain architecture and the sample history, and is correlated with special material properties. |
