Recently the researchers go to the eco-friendly corrosion inhibitors.
In the present investigation, isatin which found in many plants, Isatis tinctoria,
Calanthe discolor and Couroupita guianensis has been used as corrosion
inhibitor. An isatin-aniline compound, namely ethyl 4-amino-N-(3-isatinyl)
benzoate (AIB), was successfully synthesized in high yield and its inhibition
impact on corrosion of MS (mild steel) in hydrochloric acid as corrosive
solution was examined via weight loss and Scanning electron microscope
techniques. The results acquired appeared that AIB has employ perfect as a
corrosion inhibitor at low concentrations towards mild steel in HCl bath. The
impact of temperature on the corrosion behavior of MS in corrosive bath with
presence of (250) ppm of AIB has been investigated in the range of
temperatures (303-333) K. The thermodynamic parameters for inhibiting
process were investigated to find out the mechanism of corrosion inhibition of
MS acid bath.