Tokyo Institute of Technology · Chemistry
Professor Daisuke Aoki's research lab specializes in the design and synthesis of advanced functional polymers with dynamic and mechanically interlocked architectures. The lab focuses on developing novel synthetic strategies for cyclic, star, and topologically complex polymers using stimuli-responsive and dynamic covalent chemistry. Key research directions include the controlled synthesis of macromolecular rotaxanes and catenanes, topology transformation of polymers, and the application of mechanical bonds to enhance the mechanical properties of elastomers and polymers. The lab also explores the use of supramolecular interactions and dynamic linkers—such as disulfide-based systems and ammonium/crown ether interactions—for creating smart, responsive, and tough polymeric materials.
Figures are computed from collected data and may differ slightly.
A simple and effective synthetic route to cyclic polymers has been developed based on the following sequence: (i) selective cyclization of two self-complementary sec-ammonium-containing crown ether monomers to afford [c2] daisy-chain bifunctional initiators, (ii) living polymerization to afford the corresponding linear polymers, and (iii) a topology transformation of these linear polymers to furnish cyclic polymers. The key step in this sequence is the quantitative cyclization via self-assembly
Sacrificial chemical bonds have been used effectively to increase the toughness of elastomers because such bonds dissociate at forces significantly below the fracture limit of the primary load-bearing bonds, thereby dissipating local stress. This approach owes much of its success to the ability to adjust the threshold force at which the sacrificial bonds fail at the desired rate, for example, by selecting either covalent or noncovalent sacrificial bonds. Here, we report experimental and computat
Topology transformation of a star polymer to a linear polymer is demonstrated for the first time. A three-armed star polymer possessing a mechanical linking of two polymer chains was synthesized by the living ring-opening polymerization of δ-valerolactone initiated by a pseudo[2]rotaxane having three hydroxy groups as the initiator sites on the wheel component and at both axle termini. The polymerization was followed by the propagation end-capping reaction with a bulky isocyanate not only to pre
Macromolecular [2]rotaxanes, which consist of a polymer chain threading into a wheel component, were synthesized in high yield and with high purity. The synthesis was achieved by the ring-opening polymerization (ROP) of δ-valerolactone (VL) using a hydroxyl-terminated pseudorotaxane as an initiator with diphenyl phosphate as a catalyst in dichloromethane at room temperature. The <sup>1</sup>H NMR, gel permeation chromatography (GPC), and MALDI-TOF-MS measurements of the resulting poly(δ-valerola
A simple and efficient method to generate macrocyclic structures has been developed based on the dynamic behavior of the linker bis(2,2,6,6-tetramethylpiperidin-1-yl)disulfide (BiTEMPS). The prime linear structure was transformed into a (macro)cycle using the following sequence: 1) thiol-ene reaction with a BiTEMPS derivative to afford the linear precursor, then 2) an entropy-driven transformation induced by diluting and heating. The radicals generated from BiTEMPS upon heating are highly tolera
An effective method to synthesize mechanically linked transformable block polymer was developed utilizing functional macromolecular [2]rotaxane with a "fixed" or "movable" wheel. The interaction between a <i>sec</i>-ammonium and a dibenzo-24-crown-8-ether was the key to control the mobility of the wheel component, indicating the capability of the transformation from linear block copolymer to block/graft copolymer in which the grafting polymer chain is movable along the axle polymer chain.
The creation of polymeric materials that self-strengthen in response to a mechanical force is an important objective in the field of polymer chemistry. Here, the mechanochemical strengthening of cross-linked elastomers using macrocyclic mechanophores that contain a dynamic covalent disulfide bond is reported. Cross-linked poly(hexyl methacrylate) (CPHMA) polymers with macrocyclic mechanophores inserted at the cross-linking points were synthesized via free radical polymerization. Tensile and swel
A polymer is used as a source of fertilizer. To demonstrate the viability of this concept, the chemical recycling of poly(isosorbide carbonate) (PIC) is presented as a model for the next generation of plastic-recycling systems.
Open papers in the app to read, cite, and organize with AI.
