Synthesis and anti-corrosion performance of C₂₁H₂₅NO on corrosion of N80 steel in hydrochloric acid solution

Abstract

Purpose

In this work, a kind of Mannich base (C₂₁H₂₅NO) was synthesized with cinnamal aldehyde, acetophenone and diethylamine in a condensing reflux device based on the conventional method. Optimization of the inhibitor concentration was explored.

Design/methodology/approach

Spectral properties of this compound was investigated by FTIR, and its inhibition efficiency and mechanism on N80 steel in 20% hydrochloric acid solution were studied by weight loss measurement, electrochemical measurement (potentiodynamic polarization and electrochemical impedance spectroscopy) and surface analytical measurement (scanning electron microscope with energy dispersive spectrometer).

Findings

The results showed that the new inhibitor reduced the double-layer capacitance and increased the charge transfer resistance. The inhibition efficiency is 99.7% when the concentration of C21H25NO is 3%. The adsorption of C₂₁H₂₅NO on N80 steel surface in 20% HCl solution was found to be spontaneous and steady. Observed from the steel surface, an inhibition film was confirmed to be presented after adding inhibitor and successfully hindered the corrosive ions from reaching the bulk steel.

Originality/value

A new Mannich base (C₂₁H₂₅NO) was synthesized by cinnamal aldehyde, acetophenone and diethylamine for the corrosion prevention of N80 steel in 20% hydrochloric acid solution.

Citation

Zhu, Y., Zhao, L., Liu, P. and Qu, X. (2019), "Synthesis and anti-corrosion performance of C₂₁H₂₅NO on corrosion of N80 steel in hydrochloric acid solution", Anti-Corrosion Methods and Materials, Vol. 66 No. 5, pp. 573-582. https://doi.org/10.1108/ACMM-05-2019-2119