Electrochemical Investigation of Substituted Aniline, Melamine and Formaldehyde Based Terpolymers as Effective Corrosion Inhibitors for Mild Steel in 1M Hydrochloric Acid Solution

摘要

Three Terpolymers TERP-1, TERP-2 and TERP-3 were synthesized using melamine, formaldehydeand substituted aniline and their inhibitive action on corrosion of mid steel in 1M HCl was studiedusing electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, linear polarizationand gravimetric and weight loss methods. The inhibition efficiency of these inhibitors followed theorder TERP-3 > TERP-2 > TERP-1. Among the studied polymers, TERP-3 exhibited the bestinhibition efficiency (98%) at 50 ppm).Tafel polarization studied reveals that investigated polymers aremixed type inhibitors. EIS plot indicates that the addition of inhibitor increases the charge-transferresistance (Rct) and decreases the double-layer capacitance (Cdl) of the corrosion process, Theseobservation reveal that investigated polymers inhibits mild steel corrosion by adsorption mechanism.Various thermo dynamical parameters were also calculated to substantiate the mechanism ofadsorption.