Polymer conjugates for dual functions of reporting and hindering corrosion

Corrosion is still globally a major financial challenge and requires new materials development so that energy and resources can be saved more effectively. Suitable advanced coatings for metals shall first hinder corrosion. When corrosion still occurs, the coating shall emit a signal to allow timely maintenance before metallic structure is too much damaged. We prepared copolymers that can release corrosion inhibitors, 5-(aminomethyl)-8-hydroxyquinoline (AM8HQ) and benzotriazole (BTA), upon acidic hydrolysis of imine and hemiaminal ether linkages. Furthermore, a fluorescent molecule is attached to the copolymer via thiopropionate groups. Hydrolysis of the latter group and release of the fluorescent sensor occurs after release of the inhibitors. Corrosion rates of steel substrates coated with the pH-responsive polymers are dramatically reduced and fluorescence are detected upon onset of corrosion.