Design of Dynamic Soft Materials Utilizing Rotaxane’s Structural Characteristics (2)

Abstract

The design, synthesis, and function of dynamic soft materials utilizing the rotaxane’s structural characteristics have collected much interests of polymer scientists. Directed toward the development of the dynamic soft materials based on the linear-branched polymer topology transformation, the various linear-branched polymer topology transformation systems were constructed by using the dynamic nature of the rotaxane’s components. The topology difference between the linear and branched polymers prepared in this work could be confirmed by the difference in hydrodynamic volume, crystallinity, and morphology. In particular, three-armed star polymer-type branched polymer was synthesized using living polymerization and polymer reaction for the arm and star polymer synthesis, while the star polymer showed clear morphological difference besides those in hydrodynamic volume and viscosity toward the corresponding linear counterpart. Four-armed star polymer having two rotaxane-linked polymer chains was synthesized for the study on the physical property difference from the linear counterpart prepared by the cleavage of the attractive interaction between the rotaxane components. The physical property difference between the star and linear polymers was explained by the difference in polymer topology. Reversible linear-branched polymer topology system was constructed by the introduction of N-methyl moiety on the ammonium salt moiety placed on the axle component of the crown ether-based rotaxane structure. These results suggest the possible development of the dynamic soft materials as the stimuli-responsive polymers based on the reversible polymer topology transformation through the rotaxane’s dynamic structural control.