Poly Acrylic-Chitosan Co-Polymer as Corrosion Inhibitor for Mild Steel in 0.5 M Hydrochloric Acid Solutions

Corrosion prevention has been one of the major concerns these days various methods have been adopted for corrosion prevention. However, the use of corrosion inhibitors has proven to be the easiest and cheapest method for corrosion prevention. But then most of the conventional inhibitors are expensive and toxic. Therefore the recent focus has been turned to developing non-toxic and cheap corrosion inhibitors. To achieve that a Polyacrylic acid was successfully grafted on chitosan by the thermal method using a reflux condenser. This copolymer was characterized by FTIR, TGA, and XPS. The corrosion inhibition performance of the grafted polymer was tested on mild steel in 0.5 M HCl under different conditions by gravimetric method. Mild steel coupon was analyzed using SEM to understand the effect of the inhibitor on the mild steel corrosion. The results were subjected to various adsorption isotherm models to understand the corrosion mechanism. The weight loss results show high inhibition efficiency of 86.50432 % for 24 hrs. Immersion time at 300 °C conditions. Data best fitted with Langmuir adsorption model with a good correlation coefficient of 0.9933.