Preparation And Corrosion Inhibition Performance Of Aniline Schiff Base Corrosion Inhibitor

As an important method to avoiding the metal corrosion, organic corrosion inhibitor has become the research focus due to its simple operation, low usage amount and significant effect. Studies have shown that organic corrosion inhibitor contains an unsaturated bond and heteroatoms, such as O, N, S and P, which can be adsorbed on the metal surface to inhibit corrosion. Researches on efficient, low-cost and low-toxicity Schiff base corrosion inhibitor is one promising research field. In terms of researches on inhibition mechanism, using the method combined advanced analysis determination technique and traditional theory research method to explain the adsorption mechanism and develop environmentally friendly and cost-effective corrosion inhibitor has become the development trend of this science.In this study, the synthesis of four Schiff base compounds is achieved, including4-chloro aniline-pyridine-4-carbaldehyde Schiff base (CPA),4-chloro-4-hydroxy-aniline-2methoxybenzaldehyde Schiff base (CHMA),4-chloro4-hydroxybenzaldehyde aniline Schiff base (CHA), and4-chloro-3-phenyl acrolein aniline Schiff base (CPEA). Moreover, according to the corrosion product analysis, electrochemical impedance spectroscopy and linear polarization curves, this present work mainly focuses on the corrosion performances of the four inhibitors to carbon steel in hydrochloric acid medium, and analyzes the corrosion mechanism in the surface of the carbon steel. The research results show that the four Schiff base compounds have remarkable corrosion properties to the steel carbon in acidic media. And the inhibition mechanism is that the compound molecules adsorbed on the steel surface forms a densely protective film, thereby inhibiting the electrochemical reaction of carbon steel. With increasing amount of corrosion inhibitor, corrosion current density decreases, the charge transfer resistance increases, and the Gibbs free energy are all negative. It indicates that the adsorption is spontaneous, and the adsorption of corrosion inhibitor on the steel surface results from the combined action of physical adsorption and chemisorption.