Study On Inhibition Effect Of Triazine On Pure Lead And Lead Alloy In Sulfuric Acid Solution

Lead and its alloy is extensively used in our daily life due to its excellent performance.Howeve,it would be serious eroded in the hazardous conditions.There are not many studies on lead inhibitors,even no reports about triazine as corrosion inhibitor.Therefore,we chose 2-?2,4-dihydroxyphenyl?-4,6-bis?2,4-dimethylphenyl?-1,3,5-triazine as a corrosion inhibitor.In this paper,the protective films were prepared by molecule self-assembly systems.And the ability of triazine self-assembly film to inhibit the pure lead and lead alloy corrosion in 0.5M and 3.5M H₂SO₄ solutions were studied by electrochemical experiment,surface analysis techniques and quantum chemistry theory.The main research work and results are as follow:?1?Study on corrosion inhibition of pure lead by triazine self-assembly films in 0.5M and 3.5M H₂SO₄ solutionsTriazine films were prepared on the pure lead surface to form protective membrane against pure lead corrosion in 0.5M and 3.5M H₂SO₄ solutions.Its inhibitive efficiency was studied by electrochemical experiments.Surface analysis was proceeded to confirm the films were self-assembled on the pure lead surface successfully by Attenuated total reflection-Fourier transform infrared spectroscopy?ATR-FTIR?and contact angle?CA?measurements.According to the data analysis of electrochemical impedance spectroscopy and potentiodynamic polarization,the triazine films have good protective ability for pure lead corrosion.The inhibition efficiency of triazine films on pure lead achieved the highest value of 91.5% in 0.5M H₂SO₄ solution and 88.8% in 3.5M H₂SO₄ solution.The values of Ecorr almost no change before and after self-assemble,indicating triazine act as a mixed-type inhibitor in 0.5M and 3.5M H₂SO₄ solutions.The quantum chemistry parameter of triazine on pure lead was calculated to obtain the possible adsorption sites of triazine molecule on the pure lead surface.In addition,the influence of temperature on the corrosion inhibition efficiency was also studied in this paper.It was found that the inhibition efficiency decreased as temperature rose,and that the adsorption of triazine on pure lead surface in 0.5M and 3.5M H₂SO₄ solutions followed the Langmuir adsorption.?2?Study on corrosion inhibition of lead alloy by triazine self-assembly film in 0.5M and 3.5M H₂SO₄ solutionsTriazine films were prepared on the lead alloy surface to inhibit the lead alloy corrosion in 0.5M and 3.5M H₂SO₄ solutions.The inhibition efficiency of triazine films on lead alloy reached a maximum of 77.3% in 0.5M H₂SO₄ solution and 76.1% in 3.5M H₂SO₄ solution.The results of ATR-FTIR and CA indicated that the films were self-assembled on the lead alloy surface successfully.The inhibition efficiency declined as temperature rose,and adsorption of triazine on lead alloy surface in 0.5M and 3.5M H₂SO₄ solutions was found to obey the Langmuir adsorption.?3?Comparison between corrosion inhibition of pure lead and lead alloy in sulfuric acidWhether in 0.5M or 3.5M H₂SO₄ solution,pure lead was more easily corrode than lead alloy.Whether pure lead or lead alloy,it was more easily corrode in 0.5M than in 3.5M H₂SO₄ solution.The triazine self-assembled films have good protective ability for pure lead and lead alloy corrosion in 0.5M and 3.5M H₂SO₄ solution.Lead alloy has better corrosion resistance than pure lead.