CORROSION INHIBITION OF MILD STEEL IN SULPHURIC ACID MEDIUM BY AMBROXOL DRUG
P. GEETHAMANI *
Research and Development Centre, Bharathiar University, Coimbatore-641046, India
P. K. KASTHURI
Department of Chemistry, L.R.G. Govt. Arts College for Women, Tirupur-638604, India
S. AEJITHA
Research and Development Centre, Bharathiar University, Coimbatore-641046, India
*Author to whom correspondence should be addressed.
Abstract
Expired Ambroxol drug was evaluated as corrosion inhibitor for mild steel in 1M sulphuric acid medium by chemical, electrochemical and SEM techniques at different concentrations and temperature. The obtained result showed that inhibition efficiency increases with increasing concentration of the inhibitor. Electrochemical studies indicate that expired drug acts as a mixed type of inhibitor. The outcomes show that inhibition takes place by adsorption of the inhibitor on metal surface without altering the mechanism of corrosion process. The adsorption of Ambroxol takes place according to Langmuir`s adsorption isotherm. Thermodynamic parameters were calculated and discoursed. The data collected from the studied techniques are in good agreement to confirm the ability of using expired Ambroxol drug as corrosion inhibitors for steel in sulphuric acid aggressive medium.
Keywords: Mild steel, polarization, expired drug, corrosion inhibitor, ambroxol