Post-polymerization modification via the Biginelli reaction to prepare water-soluble polymer adhesives

Post-polymerization modification (PPM) has been widely applied to achieve new functional polymers by introducing functional groups to polymer precursors via efficient organic reactions. Most modification reactions were only studied as the coupling tools, and the unique functions stemming from the modification reactions were usually neglected. Here, a commercial monomer containing a beta-keto-ester was used to prepare a water soluble copolymer precursor, and the tri-component Biginelli reaction has been utilized as the side chain modification approach to prepare a series of new polymers. Besides giving outstanding modification performance (rapid reaction rate, similar to 100% modification yield), the Biginelli linking group also possesses the new function of adhesion. As a result, when other adhesive functional groups were introduced through the Biginelli reaction, water soluble polymer adhesives comparable to commercial glues could be realized (similar to 7.55 MPa on a brass substrate). Moreover, the copolymer containing a phenylboronic acid group is not only an effective adhesive on different types of substrates (metal, plastic, bone), but also safe in the in vivo test, indicating the potential application of this polymer in bio-related fields. All these results suggested that the introduction of functional groups through a newly generated functional linkage can be simply realized by some multicomponent reactions, opening a new way to prepare functional polymers through the PPM strategy.