Catechol isomers for moisture initiated bioadhesives

While catechol chemistry is widely known, the selection of catechols applied for resins and adhesive purposes has relied almost exclusively on L-dopamine variants. Herein five catechol isomers evaluate <i>ortho</i>, <i>meta</i>, and <i>para</i> dihydroxybenzene (DHB) structures on adhesion related mechanical properties, including organic/aqueous stability, gelation time, and adhesion strength on soft substrates. A model system evaluates the catechol-aldehyde isomers through Schiff base grafting to an amine rich macromolecule, branched polyethylenimine. This work evaluates how grafted-catechol isomers can be exploited to tune reactivity to both solvent and external stimuli. The formulations allow a range of sensitivity, from designs that observe gelation time within minutes of water exposure, to water-stable formulations that can be cured through <i>via</i> voltage stimulation.