A bioinspired and environmentally sustainable polyphenol-based water adhesive

Most commercial adhesives currently available pose significant environmental concerns due to the presence of contaminants such as volatile organic compounds (VOCs). To address this challenge, much research is being focused on developing water-based adhesives. Herein, we demonstrate that polymerisation of a natural polyphenolic compound (pyrogallol) with an amino-based ligand (tris(2-aminoethyl) amine) in water allowed for the development of a novel bioinspired water-based adhesive without involving VOCs. The reaction conditions were meticulously optimised by adjusting the reaction time, ratio, drying methodology and curing temperature, to produce a functional adhesive applicable across a broad spectrum of materials. Adhesion tests demonstrated competitive and outstanding performance on aluminium, followed by wood (oak and pine) and plastics (polypropylene, polycarbonate, and polymethylmethacrylate). Notably, the adhesive outperformed one of the most commercially used adhesives on pine and oak, highlighting its competitive advantage.