Rare earth-based corrosion inhibitors

There is now a search for less toxic, greener alternative corrosion inhibitors. Chromates have combined effectiveness with relatively low cost. Sinko has reviewed the quality parameters needed for corrosion inhibitors in coatings, and generally concluded that inorganic non-chromate inhibitors such as phosphates, molybdates, borates and silicates are inferior to chromates. Rare earth salts have been proposed and show promise as alternative corrosion inhibitors, and we have been developing rare earth carboxylates as potential dual function inhibitors combining the roles of the rare earth and the aromatic carboxylates. If rare earth-based corrosion inhibitors are to be used, there is a need to understand the chemistry of the elements and of the inhibitors. 

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