New, Amino Acid Based Zwitterionic Polymers as Promising Corrosion Inhibitors of Mild Steel in 1 M HCl

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 (E a ), standard enthalpy of activation (∆H*), standard entropy of activation (∆S*), adsorption-desorption equilibrium constant (K ads ), and standard free energy of adsorption (∆G o ads ), 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.

Inhibition Mechanism of Some Vinylalkylimidazolium-Based Polymeric Ionic Liquids against Acid Corrosion of API 5L X60 Steel: Electrochemical and Surface Studies

“…In contrast, the decomposition of the terpolymers poly[VIM4C][Br] and poly[VIM2C][Br] took place in two clearly defined stages at 245 and 250 °C, respectively. The first stage was ascribed to the decomposition of side acrylamide groups by the elimination of ammonia, forming imide groups; , at this stage, the decomposition of repeating PIL units is also found. , The second stage was related to the decomposition of the repeating units of n -vinylpyrrolidone.…”

“…101,102 at this stage, the decomposition of repeating PIL units is also found. 103,104 The second stage was related to the decomposition of the repeating units of n-vinylpyrrolidone.…”

“…The first stage was ascribed to the decomposition of side acrylamide groups by the elimination of ammonia, forming imide groups; 101 , 102 at this stage, the decomposition of repeating PIL units is also found. 103 , 104 The second stage was related to the decomposition of the repeating units of n -vinylpyrrolidone.…”

Evaluation of 1‐Hexadecylbenzimidazole as a Corrosion Inhibitor on Low Carbon Steel 15 % HCl Solution Interface

“…[10] Several efforts made on the developments of corrosion inhibition of LCS in the acidic medium were based on different classes of natural and synthetic compounds comprising of different adsorption centers and hydrophobes. [11][12][13][14] In an acidizing application where 15 % HCl is mostly used, organic compounds containing heteroatom embedded in multiple-bonded cyclic compounds are reported to be effective corrosion inhibitors. [15][16][17] Two quinoxaline derivatives having thiazole motifs have been shown to impart inhibition efficiencies of � 96 % at 303 K at a concentration of 100 ppm.…”

Impact of Degree of Hydrophilicity of Pyridinium Bromide Derivatives on HCl Pickling of X-60 Mild Steel: Experimental and Theoretical Evaluations

“…However, hydrochloric acid (HCl) pickling is preferred to other inorganic acids (hydrofluoric, sulfuric, phosphoric and nitric acids) pickling in steel mills and other steel applications industries due to its high regeneration, less pickling time, minimal loss of substrates, lower temperature and high-quality finished products [6,7]. To improve the economic importance of mild steel in pickling applications, corrosion inhibitors have been used to drastically reduce the effect of acid attack on mild steel [8][9][10].…”