光で操る再生可能バイオベース接着剤の開発

抄録

The development of tough, reusable adhesives is important but remains a major challenge, especially in water. A tough, reusable adhesive that fully returns to its original state when needed is reported using caffeic acid. Here, caffeic acid is used as an adhesive moiety to achieve these functions due to its dual properties: an adhesive moiety derived from mussel-inspired catechol and a photo-reversible crosslinking agent derived from cinnamic acid. Adhesion is a two-step process. First, the caffeic acid functionalised polymer is applied to the adherend, followed by UV irradiation at 365 nm to form a durable pre-applied adhesive（PAA）layer through cross-linking between the caffeic acid moieties. Secondly, thermal activation of the PAA layer ensures repeated adhesion to a variety of adherends（reuse-many mode）．The cyclic dimer of the caffeic acid moiety is decrosslinked by UV irradiation at 254 nm. This allows complete removal of adhesive residues from the adherends when the adhesive is no longer required（reset-on-demand mode）．Furthermore, the caffeic acid functionalised polymer can be remotely activated under water by magnetic induction heating using magnetic nanoparticles. This study paves the way for the rational design of bio-inspired adhesives that outperform nature using plant-based raw materials.