Influence of Reaction Temperature on Corrosion-Resistant Characteristics of Poly(Aniline-Co-2-Methylaniline) Coatings

The poly(aniline-co-2-methylaniline) PAMA coatings were synthesized by keeping the feed ratio 1:1 of aniline and 2-methylaniline, respectively. These PAMA coatings were deposited at different reaction temperatures, 0˚C, 15˚C, 27˚C (ambient temperature (AT)), 40˚C, and 60˚C on the low carbon steel (LCS) surface by electrocopolymerization of aniline with 2-methylaniline. This electro polymerization was carried out in an aqueous solution containing 0.2 M sodium tartrate as the supporting electrolyte. In situ characterization of these coatings was performed by cyclic voltammetry, while the corrosion-resistant characteristics of coatings against corrosion of LCS were investigated in aqueous 3% NaCl by Tafel plot. The results of the Tafel plot measurements show that the PAMA coatings synthesized at AT have the lowest Corrosion Rate, 50 times lower than uncoated LCS, and also a higher positive shift in Ecorr of 381 mV, so it provides more effective corrosion-resistant characteristics than that of 0˚C, 15˚C, 40˚C, and 60˚C against the corrosion of LCS.