Study of the effect of corrosion inhibitors on powder coatings applied on steel

In the search for viable alternatives to produce environmentally friendly organic coatings systems, this work presents the study of several inorganic anticorrosive inhibitors and their further incorporation into a polymeric matrix via powder coating technology. The selected inhibitors are commercially available belonging to the second and third generations of developed replacement alternatives for hazards chromates. Polarization curves, also in the presence of continuous flow of N2 and air gases, have been used for the characterization of the inhibitors. Succeeding, the inhibitors were embedded in powder coatings and subsequently applied onto mild steel substrate. The coated panels have been investigated by means of accelerated tests (neutral salt spray test, cathodic delamination test), natural weathering alongside electrochemical techniques such as electrochemical impedance spectroscopy. The effectiveness of the different corrosion inhibition pigments in the organic coatings has been evaluated and discussed.