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This review focuses on our novel approaches for developing functional polymers by dissociation phenomena of macromolecular complexes. One is highly swellable polymer gels, superabsorbent polymers for nonpolar organic solvents, and the other is thermo-responsive polymers at ambient temperature in nonpolar solvents. Both of them are well-known in water, but no design has ever been proposed for other media. The dissociation of the macromolecular complexes plays a key role for them. Therefore, controlling the dissociation processes in supramolecular chemistry should be another important strategy for emerged dynamic functions.
To synthesize CO2-derived polycarbonates with high Tg values, epoxides having rigid and bulky 2-norbornyl or 1-adamantyl substituents were selected as comonomers. The alternating copolymer obtained from 1-adamantylethylene oxide showed a Tg above 150 °C. This is the highest Tg among those observed for alternating copolymers obtained from CO2 and a terminal epoxide.
An immiscible blend of isotactic polypropylene (PP) and ethylene-butene-1 copolymer (EB) containing a small amount of N,N'-dicyclohexyl-2,6-naphthalene dicarboxamide as a nucleating agent to generate β-form crystals was prepared by T-die extrusion. We successfully prepared an extruded sheet in which the orientation of the PP molecules is perpendicular to the deformation of the EB particles. It is suggested that EB barely affects the crystalline form and orientation of PP. Since this sheet containing a large amount of β-form crystals exhibits an extraordinary structure, unique mechanical anisotropy is obtained.
Polydiacetylene (PDA) derivatives exhibit color change with application of external stimuli, such as heating and mechanical stress. The original layered PDA shows the irreversible color transition from blue to red with heating at the threshold temperature. Here we found that the alkyldiamine-intercalated PDA induced the different color-change properties, such as the raise of the color-transition temperature, the temperature-dependent color-change, and the reversible color change. The intercalated diamines have the stabilization effect of the layered polymer. The stimuli-responsive color-change properties can be tuned by the intercalated organic guests.
Reverse osmosis membranes have been playing a main role for the desalination of water in the world. Hydration structure of polyamide functional layer of the membrane was studied via neutron scattering and atomistic molecular dynamics simulations. Experimental and computational structure factors, S(Q), of the polyamide/water system showed good agreement. Water clusters in water-rich system were well connected to each other and formed channel-like structure. Polyamide–water interactions and polyamide-polyamide interactions, which are thought to be important to enhance the performance of the membranes, were examined in detail.
Amphiphilic incompletely condensed polyhedral oligomeric silsesquioxanes possessing various substituents and poly(ethylene glycol)s of different chain lengths have been developed. It has been elucidated that their self-association behaviors in water are dependent on the substituents and chain lengths of poly(ethylene glycol)s. Precise molecular design, excellent thermal stability, and good dispersibility have been realized at once.
