Inhibitory action of biodegradable modified vanillin on the corrosion of carbon steel in 1 M HCl

[Display omitted] ► Vanillin derived inhibitors showed good inhibition efficiency for carbon steel in 1 M HCl. ► The efficiency increased by increasing the inhibitor concentration and the exposure time. ► The mechanism was suggested as physical adsorption and obeys the Langmuir isotherm. ► The inhibitors are readily biodegradable and meet the standard environmental limits for biodegradation. The effects of two biodegradable corrosion inhibitors derived from vanillin and aminophenol (Meta: VPAP and Para: VOAP) on the corrosion of carbon steel in 1 M HCl solution were examined. The efficiency of these inhibitors on carbon steel corrosion increased by increasing the concentration and decreased by increasing the temperature. The inhibitors adsorbed on carbon steel physically and obeyed the Langmuir isotherm. The potentiodynamic measurements showed mixed-type inhibitor. The geometry of the inhibitors showed that VPAP has slightly higher efficiency in corrosion inhibition than VOAP. The inhibitors showed good biodegradability in the environment within 28 days.