Study On The Synthesis And Corrosion Inhibition Mechanism Of Quinoline And

Due to the excellent corrosion properties, quinoline and its derivatives were widely used in industrial production. In the reaction, two different quinoline quaternary ammonium salts were successfully synthesized via quinolone acted as matrix and benzyl chloride were link agent as well as benzyl bromide. Next isoquinoline as a matrix and the link agent were still benzyl chloride and benzyl bromide. Through that way, there were two different benzyl isoquinoline quaternary ammonium salts. Then the quaternizing agent was changed, that is chlorinated and brominated tetradecane were link agent, and the quinolone still acted as matrix. And two kinds of linear substituted quinoline quaternary were obtained.Static weight loss method was used to evaluate the corrosion performance of chlorinated benzyl quinoline and bromide benzyl quinoline when the1mol/L H2SO4,10%HCl and3.5%NaCl with saturated CO2were media respectively. The results showed that both the synthesis corrosion inhibitors have good corrosion performance in three different media. The inhibition efficiency increased as the addition of increasing concentration of chlorinated benzyl quinoline and bromide benzyl quinoline. Both the inhibition efficiency of the synthesis corrosion inhibitors achieved to99%when the concentration of inhibitor was5000mg/L in the1mol/L H2SO4and10%HCl with a80℃temperature. Moreover, in the3.5%NaCl with saturated CO2when the concentraton of chlorinated benzyl quinoline and bromide benzyl quinoline was80mg/L, the inhibition efficiencies was only close to90%.The inhibition mechanisms of chlorinated benzyl quinoline and bromide benzyl quinoline were discussed by polarization curves and electrochemical impedance spectroscopy. The results indicated that both the corrosion inhibitors were mixed suppress absorption inhibitor. The scanning electron microscope and energy dispersive spectroscopy showed that the corrosion of A3steel was effectively decreased as the addition of the corrosion inhibitors, due to the reduction of oxygen element and the increase of iron element on the surface of A3steel. The adsorption thermodynamics to the A3steel with synthesis corrosion inhibitors in three media revealed that the adsorption process on the A3steel surface was spontaneous, which obeyed the Langmuir isothermal adsorption model. The adsorption process was the result of physical adsorption and chemisorption interaction.Compared among the quinolinic quaternary ammonium salts in the1mol/L H2SO4medium, the anti-corrosion property strength were bromo tetradecyl quinoline> benzyl bromide quinoline> benzyl chloride quinoline> benzyl bromide isoquinoline> benzyl chloride isoquinoline> chloro tetradecyl quinoline. From the results it can be seen that different chlorine and bromine in the quaternary ammonium reagents have a certain impact on the corrosion performance of quaternary ammonium salt. When the experiment medium was H2SO4and there was only the quaternary ammonium salt containing halogen iron, the bromo-substituted quinoline quaternary ammonium salt has a better inhibition performance than the chloro-substituted quinolone quaternary. The corrosion inhibition performance was evaluated by removing chloride ions of benzyl chloride quinolone and making complex experiment with KCl and KBr. And the corrosion inhibition effect of the bromo-substituted quinoline quaternary ammonium salt was superior to the chloro-substituted quinolone quaternary. That’s because of the Br’have a better complexing ability than the Cl-and the bromo-substituted quinoline quaternary ammonium salt have a higher degree of quaternary ammonium.