Preparation of Eco-Friendly Acidic Corrosion Inhibitors from Ilex Chinensis Sims Leaves

Abstract

Preparing chemicals from natural product is a simple way to green chemistry. May flavonoids and protocatechuic acid have been found in Ilex Chinensis Sims leaves extracts, which indicates its extracts suitable to be used as an effective corrosion inhibitor. Extracts of Ilex Chinensis Sims leaves (HE) were modified with hydroxymethylation reaction and Mannich reaction to produce the relative stable green acidic corrosion inhibitors (HM1 and HM2). The extracts of Ilex Chinensis Sims leaves and the modified samples were investigated on the corrosion inhibition of A3 steel accordingly. The results show that these inhibitors have effective corrosion inhibition effect on A3 steel. The HM2 are the most effective for corrosion inhibition, and the inhibition efficiency can reach to 78.36%. At 60 °C, the corrosion inhibition efficiency of these three extracts is HM2 > HM1 > HE. And the extracts inhibit corrosion mainly by adsorption mechanism. This adsorption accords with Langmuir adsorption isotherm.