1-Dodecyl-4-(((3-morpholinopropyl)imino)methyl)pyridin-1-ium bromide as a novel corrosion inhibitor for carbon steel during phosphoric acid production

•Novel cationic surfactant is a good inhibitor for carbon steel in 7 M H3PO4.•The maximum performance obtained was 97% at 5 × 10−3 M of inhibitor at 20 °C.•Inhibition efficiency is decreased when temperature is increased within 20–80 °C.•The inhibitor acts as a mixed-type and its adsorption obeys Langmuir isotherm.

The corrosion inhibition properties of novel cationic surfactant on carbon steel in 7 M H3PO4 solution have been determined by weight loss, Tafel polarization and electrochemical impedance spectroscopy (EIS) methods. The results revealed that the synthesized cationic surfactant is a good corrosion inhibitor. The inhibition efficiency increases with increasing the inhibitor concentration but decreases with the temperature increasing. The adsorption of inhibitor was found to obey the Langmuir adsorption isotherm. Potentiodynamic polarization studies showed that the inhibitor acts as a mixed-type inhibitor. EIS results were analyzed to model inhibition process through appropriate equivalent circuit model.

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