Study On The Synthesis Of Imidazoline Phosphonoamide Hydrochloride Salt And Corrosion Inhibition Performance

The oil-soluble imidazoline was synthesized by using naphthenic acid and diethylen triamine as raw materials,then the water-soluble imidazoline phosphoronamide hydrochloride salt(IPAH) was synthesized from imidazoline and phosphorus oxychloride.Through researching on the step of synthesis,different reaction conditions to the influence of the result were investigated,and the optimum reaction condition was obtained.The corrosion inhibition effects of IPAH in HCl and H₂S solution and the simulated oil field water were investigated by static weight loss method and electrochemical polarization curves.During the synthesis of IPAH,the different factors such as the ratio of reactants(imidazoline to phoshpror oxychloride),reaction time,temperature and solvent effected on the synthesis were studied,and the optimum reaction condition was obtained through tests:the ratio of naphthenic imidazoline to phoshpror oxychloride is 3:1,the maximum temperature is about 200℃,the reaction time is about 6h,and the solvent is anhydrous ethanol.The researches on the inhibition performance of IPAH in HCl and H₂S solution show that: IPAH attains good inhibition on the corrosion of A3 carbon steel,and the inhibition effect is increasing as the concentration of IPAH increases.The corrosion inhibition performance of IPAH is worse as the experiment temperature rises.It's also decrease when the concentration of H₂S is increasing,but the affect is small,then doesn't change at last.Finally,the corrosion inhibition rate first increase and then decrease as the experiment time extends.The researches on the inhibition performance of IPAH in the simulated oil field water show that:IPAH has a optimum concentration in the media.And the inhibition performance is effected by the pH value of the solution.The corrosion inhibition is best when the pH value is 5.And it is effected by the oxygen in the solution.When the oxygen is eliminated,the corrosion inhibition is much better.The results obtained from electrochemical polarization curves show that:IPAH is a mixed inhibitor which mainly inhibites the solvent of the carbon steel in anode and also inhibites the cathodic process in HCl and H₂S solution.IPAH is an inhibitor which inhibites the cathodic process in the simulated oilfield water.Therefore,IPAH is an inhibitor which inhibites the anode and cathodic reaction of carbon steel corrosion.