Corrosion prevention has been a global phenomenon, particularly in metallic and construction engineering. Most inhibitors are expensive and toxic. Therefore, developing nontoxic and cheap corrosion inhibitors has been a way forward. In this work, L-arginine was successfully grafted on chitosan by the thermal technique using a reflux condenser. This copolymer was characterized by Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and X-ray diffraction (XRD). The corrosion inhibition performance of the composite polymer was tested on mild steel in 0.5M HCl by electrochemical methods. The potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) results were consistent. The inhibition efficiency at optimum concentration rose to 91.4%. The quantum chemical calculation parameters show good properties of the material as a corrosion inhibitor. The molecular structure of the inhibitor was subjected to density functional theory (DFT) to understand its theoretical properties, and the results confirmed the inhibition efficiency of the grafted polymer for corrosion prevention.

Purpose: Many researchers reported the use of chitosan in various applications due to its desirable properties, but then its application in a certain condition is limited due to its lower mechanical stability, lower solubility in certain solvents, and crystallinity of the polymer. Numerous report has been published by many researchers across the world modifying chitosan to enhanced its properties thereby improving its application in various field Methodology: Poly (2-dimethylaminoethyl methacrylate) (Cs-g-PDMAEMA) were successfully synthesized by Ultrasonic methods for the first time. The synthetic method was optimized by varying various reaction parameters and reaction conditions. The grafting was confirmed by characterizing the copolymer with FTIR, XRD, XPS, SEM, TGA, DTG, and DTA.  Findings: The results show a good percent grafting and percent yield up to 132%G and 94.7%Y at optimum condition, and also shows a decrease of thermal stability and crystallinity of chitosan, there was improved in porosity of the surface, and complexity of the surface functional group making it a good candidate for metal chelating. Observing various changes in the spectrum of these derivatives and that of pure chitosan in addition to the change in properties of these polymers such as surface morphology, thermal stability, and crystallinity. Uniqe Contribution to Theory, Practice and Policy: It was suggested that this modification may improve the application of these polymers.   KeyWords: Chitosan, Cs-g-PDMAEMA, Ultrasonication, Grafting

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.