The Prepapation And Perfoermance Research Of Inorganic Zinc-Rich Rust Coatings

Metal corrosion has severely hindered the economic development and the country industrialization.Therefore,the exploitation of the environment,efficiency and simple construction protection coatings for metal was significant.Due to the excellent water,weather,corrosion resistance and self-repairing properties,the inorganic silicate zinc-rich coating has shown the great potential in the field of metal protection.However,because of the large silicate solution fluidity,the high zinc powder and the high construction requirements,traditional silicate zinc-rich coatings were limited.In view of the above problems,this paper from two aspects of silicate solution and zinc powder to improve the corrosion resistance of the coating,achieve rusty coating,and simplify construction process.The main research contents of this paper are as follows:(1)Studied on composition and properties of the silicate film-forming system.Potassium silicate and lithium silicate as film-forming material.The type and amount of silane coupling agent,temperature,modulus and the dropping speed of silica sol on viscosity,stability,water resistance,and particle size of the silicate solution was studied by observation and DLS tests.The silicate solution synthesis process was optimized.The results showed that the silicate solution prepared by using KH560 as coupling agent,controlling temperature at 50?,and adding the same quality silica sol with the rate of 4 mL/min has great film-forming performance.(2)Studied on the effect of modified silicate coating by aqueous organic emulsions.The effects of the different amounts of emulsions on the corrosion resistance and construction performance of the coatings were compared by NNS and EIS.The results showed that the proper amount of emulsion could significantly improve the corrosion resistance of the coating.Compared with the unmodified coating,the self-corrosion potential of the coating doped with 0.5 g emulsion was shifted by 310 mV and the corrosion current decreased by 2.832×10-4 mA after soaking in 3.5%NaCl 50 days.The corrosion resistance of coating was significantly improved,and the rust coating of the coating can be realized,which greatly simplifies construction steps in practical application(3)Studied on the effect of modified zinc on the properties of the coatings Synthesized NO3-,VO3-,M0O4-' intercalated ZnAl/LDH on the zinc surface by hydrothermal method,and the surface morphology and structure of modified zinc was characterized by SEM,HRTEM,XRD,etc.Modified zinc was mixed with silicate solution to prepare the variety LDH loaded silicate zinc-rich coatings.The corrosion resistance of the coating was investigated by EIS.Results showed that the LDH presents laminar microstructure on the surface of zinc powder,which significantly delayed the penetration rate of corrosion ions and played important role in the metal protection process.Electrochemical results showed that the ZnAl-VO3-/LDH coating has better corrosion resistance.Compared with the unmodified coating,the self-corrosion potential was shifted by 29 mV and the corrosion current decreased by 2.190× 10-3 mA after soaking in 3.5%NaCl 30 days.