Synthesis of Mannich Base Acidizing Corrosion Inhibitor and Evaluation of Its Inhibition Performance

A Mannich base acidizing corrosion inhibitor was synthesized by Mannich reaction with acetophenone,formaldehyde,and diethylamine as the starting materials,water as the solvent,and benzyltriethyl ammonium chloride as the phase-transfer-catalyst.The effects of inhibitor concentration and corrosive solution temperature on the inhibitory effectiveness were investigated with weight loss method and electrochemical method.Results showed that the inhibitor was mixed-type,and it was physically adsorbed on the surface of carbon steel.The corrosion inhibition rate decreased gradually with the rise of temperature,and it increased initially but declined later with increasing concentration of inhibitor.Particularly,when the dosage of the inhibitor was 0.7%(mass fraction) and the temperature of the corrosive solution was 35~55 ℃,the inhibition efficiency was above90%,which indicated that as-synthesized inhibitor could effectively retard the corrosion of carbon steel by HCl solution.