Study On The Preparation And Application Of Vapor Corrosion Inhibitors That Based Bimorpholine Methylurea For Carbon Steel

Atmospheric corrosion is inevitable for metal products under normal storage and transportation conditions.Vapor phase corrosion inhibition technology is green,efficient,economical,and practical,and is considered to be one of the most practical methods to protect metals from corrosion.In recent years,the research on vapor corrosion inhibitors（VCIs）has received widespread attention,especially the research on green and efficient VCI formulations,and the improvement of the corrosion inhibition performance of their derived anti-rust products,such as anti-rust paper and anti-rust film,It is of great significance to promote its practical application.Based on this,this work takes 45^#steel as the research object,optimizes the compound VCI formulation,produces anti-rust paper and anti-rust film,and studies their properties.The main content is focused on the following aspects:（1）A Mannich base called Bis-morpholiumomethyl-urea（BMMU）was prepared from urea,formaldehyde,and morpholine by Mannich reaction.BMMU was used as a corrosion inhibitor.Through rapid vapor phase screening experiments and closed reduced mass volatilization experiments,urea and sodium dodecyl sulfonate（SLS）were selected,and the three components were classified as three factors in the VCI formulation.Through potentiodynamic polarization curves and impedance spectroscopy testing,three levels of three factors were selected,and an L9（₃³）orthogonal experiment was established.In response to the corrosion inhibition efficiency,the optimal ratio of VCI formulation was obtained through range analysis as follows:m BMMU:m_urea:m SLS=3:2:0.25.The corrosion inhibition efficiency was94.05%calculated by mass loss.（2）According to the above VCI formula(the ratio is:m BMMU:m_urea:m SLS=3:2:0.25),it is prepared into a solution,and a vapor phase antirust paper is prepared by immersion method.The results of Hanging test and SEM showed that the metal samples packaged with the vapor phase antirust paper produce less rust than the base paper;The vapor phase corrosion inhibition ability（VIA）experiment showed that the anti-rust ability of the vapor phase anti-rust paper reached level 0,with good anti-rust ability;In the contact corrosion experiment,the vapor phase antirust paper directly contacts the metal,which will not cause corrosion and deterioration on the metal surface;The contact angle test shows that the contact angle of the metal surface protected by the antirust paper increases by about 11°compared to the base paper,presenting a higher hydrophobicity.The mechanism of volatilization of the composite VCI formula onto the metal surface was analyzed by XPS.After successful adsorption of VCI onto the metal surface,on the one hand,VCI molecules coordinate with Fe vacancies,inhibiting the electrochemical corrosion reaction of the metal,on the other hand,improving the hydrophobicity of the metal surface,reducing the possibility of corrosion caused by metal contacting with water in the atmospheric environment.（3）Using PVA1799 as the matrix,it is completely soluble in water and then added with composite VCI(ratio:m _BMMU:m_urea:m _SLS=3:2:0.25),Tween 80,OMA,chitosan,and sodium phytate to form a peelable water-based rust preventive solution.The addition of OMA can greatly improve the dispersion of the solution and promote the adsorption of a complete peelable film on the metal surface.After the addition of chitosan or sodium phytate,the average discoloration time in the copper sulfate droplet experiment increases from 3.33 seconds to 6 seconds and 4.44 seconds,respectively,improving the ability of the antirust liquid to form a film on the metal surface and resist the erosion of acidic media,and both can form a complete and unbroken peelable protective film on the metal surface;After 1 minute of testing with the testing solution,there were no blue-green spots formed,indicating that the protective film has qualified rust prevention effect.The formulation will continue to be optimized and improved in the later stage,with the potential to be compounded into a highly effective peelable water-based rust preventive fluid.