Improving performance of epoxy painting by adding some organic inhibitors to decrease corrosion of AISI-1020 Carbon Steel

Development of a new environmentally safe painting for corrosion protection of metallic surfaces attracted great interest in material science through the past few years. Smart painting showed promising corrosion protection of metals and alloys in different technological applications due to releasing the active agents of the paint in a controllable manner for preventing cracks propagation in the protective paint. These painting possess passive matrix functionality and actively responds to changes in the local environment which make it prompted great interest from material scientists. Characterization and improving performance of epoxy painting by adding organic inhibitors for AISI-1020 Carbon Steel was done, three organic inhibitors were used (tannic acid, polyethylene glycol, and quaternary amine). The experiments showed that, tannic acid has the most effective results by forming a protective film with substrate and inhibiting the accessible reaction sites exposed to the corrosive media. Thickness was measured for the three samples of different inhibitor content, where the thicknesses were nearly the same because using the same technique of paint application, the thickness was 164 μm, also roughness was measured for paintings containing tannic acid, polyethylene glycol, and quaternary amine painting and the result was 15,12 and 13.5 (μm) respectively. Adhesion test was performed on the different three painting and the result was 400, 360 and 340 N/m2 respectively. Also scratch test in 7 % NaCl was done, salt spray test was done for 6 days and glossy test and spacemen painted by epoxy containing tannic acid shows better condition of corrosion.