2-Aminopyridine as an effective inhibitor for the corrosion of mild steel in acidic solutions

The inhibition action of 2-aminopyridine (2-AP) on acid corrosion of mild steel was studied by weight loss and potentiostatic polarisation measurements. 2-aminopyridine (2-AP) has a very good activity as mild steel corrosion inhibitor under different conditions. The inhibitive performance of 2-AP is due to multiple interaction model involving two coordinate bondings and a further hydrogen bonding interaction between 2-AP molecule and the metal surface. It behaves predominantly as cathodic inhibitor in HCl and mixed inhibitor in H ₂SO₄ The inhibitor brings down the permeation current more effectively in acid solutions. The adsorption of 2-AP on mild steel from acid solutions is found to obey Langmuir's adsorption isotherm.