Experimental and theoretical studies on protective properties of poly(pyrrole-co-N-methyl pyrrole) coatings on copper in chloride media

The corrosion inhibition behaviour of poly(pyrrole-co-N-methyl pyrrole) films synthesized from oxalic acid solutions containing different ratios of monomers (Py:NMPy 8:2, 6:4, 5:5, 4:6, 2:8) has been examined. For this aim, Eocp–time curves, anodic polarization and EIS techniques were used. Synthesized copolymer films exhibited significant protection efficiency against corrosion of copper in 3.5% (w/v) NaCl and 8:2 ratios of monomers gave the most protective copolymer coating. Quantum chemical approach was utilized in order to correlate corrosion inhibition performance of all copolymers. Experimental protection efficiencies are supported by density functional theory (DFT) calculations.

► Corrosion performance of copolymer films was investigated in 3.5% NaCl solution.
► Copolymer synthesized from 8:2 ratio of Py:NMPy is the most effective coating.
► Corrosion behaviour of copolymer films was supported by DFT calculations.