Abstract
The zwitterionic monomers, N,N’-diallylamino propanephosphonate and amino acid residual N,N’-diallyl-l-methionine hydrochloride were synthesized, with excellent yields. These monomers were utilized in the preparation of zwitterionic homo and co-cyclopolymers 5–7 in aqueous solution using 2,2′-azobis (2-methylpropionamidine) dihydrochloride as an initiator. The polymers were characterized by FT-IR, NMR, and TGA. The performance of these synthesized polymers on mild steel in acidic solution was investigated by gravimetric method, Tafel extrapolation, linear polarization resistance, and electrochemical impedance spectroscopy. At 313 K, the maximum inhibition efficiencies of corrosion inhibitors 5–7 at 4.50 × 10−4 mol L−1 were found to be 85.2%, 83.3%, and 99.5%, respectively. The inhibition efficiencies obtained from gravimetric weight loss, potentiodynamic polarization, and electrochemical impedance spectroscopy measurements were in good agreement. Different adsorption isotherms were also explored to find the best fit, and found to obey Langmuir adsorption isotherm. The thermodynamic parameters, such as activation energy (Ea), standard enthalpy of activation (ΔH*), standard entropy of activation (ΔS*), adsorption–desorption equilibrium constant (Kads), and standard free energy of adsorption (ΔGoads), were determined. Electrochemical data indicated that the zwitterionic copolymer 7 acts as a mixed type inhibitor under the influence of anodic control. The surface morphology of mild steel corrosion was evaluated without and with corrosion inhibitors by AFM, SEM-EDX, and XPS, which confirmed the adsorption of inhibitor molecules on the metal surface.
Highlights
The inexpensive and readily available mild steel has very high iron content (>99%), which has been appeared as a subject of durative studies in the field of corrosion due to its high mechanical and technological values, and found huge industrial applications, in petroleum industries [1].Corrosion is considered a destructive process of metal and alloys, which occurs due to chemical and electrochemical reactions with the companion environments
The inhibition efficiencies and adsorption behavior of these newly synthesized zwitterionic polymers on mild steel corrosion were studied by gravimetric, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) methods, Triethyl phosphate, 1,3-dibromopropane, and diallylamine were purchased from Sigma Aldrich
We were apprehensive about the polymerizability of zwitterionic monomer, under free radical conditions in the aqueous solution, readily undergoing cyclocopolymerization in the presence of water-soluble free radical initiator azobis(2-methylpropionamidine) dihydrochloride (AMPD) to give zwitterionic polymers 5–7 at very good yields
Summary
Corrosion is considered a destructive process of metal and alloys, which occurs due to chemical and electrochemical reactions with the companion environments. It is an aggressive process, and generates constant, continuous and huge financial costs to health and the environment, and safety losses for the industrial and metallic resources that eventually appear with a great concern to both industry and society [2]. Considering the impacts on health and safety, and economic losses, different kinds of preventative technologies have been developed and implemented, depending upon the nature of metal, to control, reduce, or eliminate corrosion
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
