Research Theme
Adhesion system using supramolecular materials
Light-stimuli-responsive, easily dismantled adhesive material using movable cross-linking
In recent years, there has been a need to develop adhesives that combine high adhesive stability and easy disassembly. We prepared a polymeric material capable of cleaving crosslink points upon photo stimulation by mixing a photoacid generator that generates acid upon UV irradiation with a movable crosslinked polymeric material; acetylated γCD monomer (TAcγCD) with an acid degradable bond to EA was mass polymerized in the presence of a photoacid generator, Bis (cyclohexyl sulfonyl PEA-TAcγCD/BCSD exhibited higher Young's modulus and toughness than linear polymers (PEA) due to the introduction of mobile cross-links (Figure a). Young's modulus was significantly reduced by cleaving the movable cross-links upon UV irradiation (Figure b), and PEA-TAcγCD/BCSD was successfully bonded to homogeneous or heterogeneous substrates, and the bond strength was reduced by UV irradiation (Figure c). In addition to the introduction of mobile cross-links, cleavage upon photostimulation resulted in both high adhesion stability and easy disassembly
(c) Change in adhesive strength before and after UV irradiation
Matsumura, Y.; Yamaoka, K.; Ikura, R.; Takashima, Y.,
Light Stimuli-Responsive Degradable and Tough Polymeric Materials with Movable Crosslinks
ACS Applied Materials & Interfaces 2025
Movable cross-linked adhesive sheet with both toughness and recycling
Pressure-sensitive adhesives (PSAs) are designed with the introduction of appropriate cross-linking. However, the crosslinked elastomers have extremely low solubility, making them difficult to recover and recycle. By replacing the cross-linking moieties with unique movable cross-links, a movable cross-linked PSA was obtained that forms a microgel and dissolves in solvents. This new PSA repeatedly exhibits mechanical properties and excellent adhesive properties upon dissolution and drying. As a new and recyclable PSA, we will analyze the detailed mechanism and study further performance improvement.
Kosaba, S.; Ikura, R.; Yamaoka, K.; Arai, T.; Takashima, Y.,
Recyclable Tough Adhesive Sheets with Movable Cross-links for Sustainable Use
ACS Applied Materials & Interfaces 2024, 16 (19), 25393-25403.
To achieve stable adhesion between dissimilar materials, an adhesion system that combines high adhesive strength with excellent toughness is required. In this study, a new adhesion system using a single mobile cross-network (SC) material (SC(DMAAm) Adh) was designed. The mobility of the main chains is adjusted by the water content, which determines the optimum state. The results show that SC(DMAAm) Adh exhibits excellent cohesive properties at appropriate water content.
Qian, Y.; Ikura, R.; Kawai, Y.; PARK, J.; Yamaoka, K.; Takashima, Y.,
Improvement in Cohesive Properties of Adhesion Systems using Movable Crosslinked Materials with Stress Relaxation Properties
ACS Applied Materials & Interfaces 2024, 16 (3), 3935-3943.
