Improving the Corrosion Performance of Epoxy Coatings by Modification with "Active" and "Non-active" Silane Monomers

The improvement of corrosion performance of epoxy coatings by modification with "active" and "non-active" silane monomers is presented. "Active" silanes are defined as ones having functional groups that can react with the epoxy group, usually amino-group silanes. "Non-active" silanes are not involved in a ring-opening reaction, but can be grafted onto the epoxy backbone by the condensation reaction between methoxy or ethoxy group in silanes and hydroxyl groups in the epoxy resin using an organic tin compound as the catalyst. FTIR spectroscopy results showed that both possible target reactions had successfully taken place between "active"/"non-active" silanes and epoxy resin. Electrochemical impedance spectroscopy (EIS) and accelerated corrosion tests (e. g. Machu test and boiling water test) show that the modified epoxy coatings provide better corrosion performance.