Ranitidine Drugs as Non-Toxic Corrosion Inhibitors for Mild Steel in Hydrochloric Acid Medium

Abstract

Expired ranitidine was tested as a corrosion inhibitor for mild steel in 1 M HCl using different techniques: weight loss, potentiodynamic polarization, open circuit potential and electrochemical impedance spectroscopy. The polarization resistance (R p ) value increased with increase in the concentration of the inhibitor. Results obtained revealed that ranitidine performed excellently as a corrosion inhibitor for mild steel in this medium at 303 K. The protection efficiency increased with increasing inhibitor concentration. The maximum protection efficiency of 90% has been obtained at 400 ppm. On the other hand, the efficiency decreases with increasing temperature. The adsorption of the inhibitor on the mild steel surface followed Langmuir adsorption isotherm model. The activation and thermodynamic parameters of dissolution and adsorption were calculated and discussed. The negative value of ∆G ads (-40 kJ mol

Effect of temperature on the crack growth in pipe steel X70 in a weakly acidic electrolyte

“…However, the E a values exceed 20 kJ/mol (Table 1); this indicates that a surface reaction is the stage determining the crack growth [26]. It is believed that it is the formation of an activated complex on the metal surface upon the metal ionization [21][22][23][24][25], and this stage generally determines the rate of the overall anodic dissolution of iron or steels in acidic electrolytes.…”

“…It is of interest to compare the E a values (Table 1) with the activation energy of corrosion of carbon steels and low-alloyed steels in acidic electrolytes. In fact, the following corrosion activation energies were obtained for carbon steel in 1 M HCl: 27.9 [21], 40.37 [22], and 55.75 kJ/mol [23]. A study of the corrosion of low-alloyed pipe steels gave 59.73 kJ/mol for X60 steel in 1 M H 2 SO 4 [24] and 36.76 kJ/mol for X70 steel in 0.5 M HCl [25].…”

Studies on the inhibition of carbon steel corrosion in hydrochloric acid solution by expired Carvedilol drug

“…These properties would validate their use as corrosion inhibitors in various media. Likewise, the use of expired drugs as non-toxic corrosion inhibitors for CS and Al in acidic media was reported before (7)(8)(9)(10)(11). The use of expired drugs as corrosion inhibitors can be traced back to 2009's and 2011's when Abd El-Hameed (7) used expired ranitidine as corrosion inhibitor for carbon steel (8) and for mild steel (8) in HCl corrosive medium, respectively.…”

Synthesis, characterization, and evaluation of some acyclic S-nucleosides of pyrazolo[3,4-d]pyrimidine-thiones as corrosion inhibitors for carbon steel in hydrochloric acid

“…The linear variation of weight loss with time in uninhibited and inhibited 1.0 M HCl indicates the absence of insoluble surface films during corrosion. In this case, the inhibitors are first adsorbed onto the metal surface and thereafter impede corrosion either by merely blocking the reaction sites (anodic and cathodic) or by altering the mechanism of the anodic and cathodic partial processes [21][22][23][24]. …”

“…The inhibition efficiency decreased with increase in temperature, leading to the conclusion that the protective film of these compounds formed on the steel surface is less stable at higher temperature; which may be due to the desorption of some adsorbed molecules from the surface of the steel at higher temperature due to which greater area of the metal is exposed to the acidic environment. The apparent activation energy (E a ) of metal corrosion in acid media can be calculated from the Arrhenius equation [20][21][22][23][24][25]: …”