1Department of Chemistry, Govt. College of Technology, Coimbatore.
2A.C. College of Engineering and Technology, Karaikudi - 630 004, India.
3Central Electro Chemical Research Institute, Karaikudi - 630 003, India.
The Influence of acid extract of Acalypha indica on the corrosion of mild steel in 1M H2SO4 has been studied by weight loss method. It is found that the plant extract shows better inhibition action in 1M H2SO4. The Inhibition efficiency increases with the inhibitor concentration and immersion time. The effect of temperature on the corrosion behaviour of mild steel in1M H2SO4 with and without inhibitor was studied in the temperature range from 298K to 343K. Thermodynamic parameters like activation energy (Ea), free energy of adsorption (ΔGads) Enthalpy of adsorption (ΔH) and Entropy of Adsorption (ΔS) were calculated. The adsorption of the inhibitor on the metal surface obeys the Langmuir adsorption isotherm. The inhibition action of the plant extract may be due to the presence of phytochemical constituents like Aclyphine and Aclyphamide.
Mildsteel, sulphuric acid, corrosion inhibition, Langmuir adsorption isotherm, Acalypha indica
