ECO-FRIENDLY INHIBITOR FOR CORROSION OF TMT ROD IN MARINE ENVIRONMENT

Metal structures play important role in our day-to-day life. Metallic structures are used in most of the industries in almost all the stages of the processes. Naturally, metals deteriorate and its unavoidable but controllable. Construction of buildings in marine environment is challenging in terms of both economically and scientifically. Billions of rupees are lost due to corrosion, especially due to marine environment. One of the methods to prevent loss due to corrosion is application of chemical inhibitors. Among them chromium exhibited excellent results against corrosion of metals. Meanwhile, chromium based inhibitors possess toxicity to the benign environment. In this view, chromium based inhibitors are banned from use. This scenario increased the interests of researchers towards eco-friendly inhibitors.

It has been demonstrated that organic compounds derived natural resources can protect the metal corrosion significantly. Plants are economical sources of naturally available organic compounds. In this view, the extract obtained from the leaves of Milletia Pinnata was used to protect the surface of TMT rod in marine environment in this study. TMT rods with predetermined weights are used for this study. The experiment was performed using water with 33 ppt of salinity. The TMT rods were placed in the saline water for 24 h. The change in the weights of the TMT and inhibition efficiency were calculated based on weight loss method. Further, the effect of number of coatings were also varied.

The results indicated that the TMT rods coated with the plant extract (10 coatings) exhibited inhibition of about 90% of corrosion. Further, Langmuir adsorption isotherm indicated that the mechanism of inhibition follows physisorption predominantly.