Main Chain-Type Polyrotaxanes Derived from Cyclodextrin-Based Pseudo[3]rotaxane Diamine and Macromolecular Diisocyanate: Synthesis, Modification, and Characterization

Abstract

We prepared main chain-type polyrotaxanes by urea bond-forming polyaddition of a diamine axle-containing αcyclodextrin (α-CD)-based pseudo[3]rotaxane to a macromolecular diisocyanate derived from poly(propylene glycol). Bulky isocyanate or aniline used as a comonomer worked as an effective stopper during the key step of the polyrotaxane synthesis. In the polymer preparation, the chain extension method worked effectively to increase the polymerization degree. Polyrotaxane was modified by the main chain extension and the cross-linking of hydroxyl groups of the CD wheels. The morphology and the effect of the rotaxane structure on the thermal and physical properties were evaluated. Some polymers exhibited sufficient toughness for industrial use. Because diamine-type pseudo[3]rotaxane is easily obtained on a large scale (100 g in a 1 L flask) from α-CD and 1,12diaminododecane, this study contributes to the synthesis of various polyrotaxanes for actual use.

Alcohol Moiety-Tethering Acylazides as Versatile Isocyanate Precursors for Polymerization Initiators and Monomers

“…Since the connecting part of the block polymer could affect the property of the material, this point would be also considered as an advantage. The above-mentioned synthetic approach may broaden the range of attainable molecular designs of polyurethane species, which are produced on a large scale at an industrial level, so that they can be studied as modern functional materials. − Against this backdrop, herein, we designed an orthogonal alcohol species comprising an acylazide moiety that could be used as a precursor of the isocyanate group, and we demonstrated the utility of this species in the facile preparation of an end-reactive polyester, polyurethane, and a block copolymer (Figure ). Furthermore, based on the initial result with 1 , 2 was developed as the catalyst-free agent.…”

Cyclodextrins‐Based Polyrotaxanes: From Functional Polymers to Applications in Electronics and Energy Storage Materials

“…(b) Pseudo (3) polyrotaxane composed of 1,12‐diaminoalkane and cyclodextrins acted as a chain extender for controllable coverage. Reproduced with permission [71] . 2020, American Chemical Society.…”

“…In essence, the coverage ratio could be finely tuned by extending the length of the axle during the sealing process. Different from extending the length of PEG, Akae et al [71] introduced rotaxane structure in the synthesis of linear polyurethane, in which pseudo(3)polyrotaxane composed of 1,12-diaminoalkane and cyclodextrins acted as a chain extender (Figure 3b). It is worth mentioning that bulky phenyl isocyanate can effectively prevent cyclodextrin from sliding off.…”

“…Reproduced with permission. [71] 2020, American Chemical Society. (c) Polyrotaxanes with well-defined threading ratio by replacing cyclodextrin with hydroxypropyl cyclodextrins.…”

Crystal Habit Modification of Metronidazole by Supramolecular Gels with Complementary Functionality

“…The bis(isocyanate) was synthesized according to a reported procedure. 46 Yield: 95.0%. 1 H NMR (400 MHz, chloroform-d) δ 6.87 (s, 4H), 3.85 (s, 2H), 2.65 (q, J = 7.6 Hz, 8H), 1.22 (t, J = 7.6 Hz, 12H).…”