Broadening the Chemical Space of Mussel-Inspired Polymerization: The Roll-out of a TCC-Polymer Platform with Thiol-Catechol Connectivities

The mussel-inspired polymerization (MIPoly) of bisquinone (AA type) and dithiol (BB type) monomers utilizes room temperature Michael-type polyaddition to form polymers with adhesive thiol-catechol connectivities (TCCs) in their backbone. The combination of five bisquinones and eight dithiols proves the generic character of this robust polymerization and leads to a TCC-polymer library with 40 different polymers. The set of adhesives is investigated in detail, and structure-property relationships are studied, analyzing material properties and adhesive capabilities. Dry adhesive tests are carried out under hot-meltlike conditions, revealing adhesive strengths up to 2.40 MPa for gluing aluminum and 1.26 MPa for polypropylene. A selected set of TCC adhesives is further studied under seawater-model conditions for the wet-gluing and wet-curing of technical aluminum substrates. The library approach offers access to novel adhesives in the field of mussel-inspired glues as shown by seawater-tolerant adhesives that are providing adhesive strengths of up to 1.25 MPa under hostile high-salt conditions.