Preparation Of Mesoporous Titanium Dioxide Modified With Polyethyleneimine And Research On Its Application In Anti-corrosive Coatings

In this paper,mesoporous TiO₂ was prepared,then it was modified with polyethyleneimine,and its influence on the anti-corrosive properties of the coating was investigated.1.The mesoporous TiO₂ was prepared by the sol-gel method.Tetrabutyl titanate?TBOT?was used as the titanium source and hexadecyl trimethyl ammonium bromide?CTAB?was used as the template.Then the effect of different process or conditions on the mesoporous TiO₂ crystal shape,particle size,morphology and pore size was investigated.The samples were characterized with XRD,BET,FT-IR and TEM.The results showed that,compared with those with the high temperature calcining method,the mesoporous TiO₂ obtained with solvent extraction method was the most suitable for the water-based anti-corrosive coatings.The mesoporous TiO₂ obtained with solvent extraction has a specific surface area of 124.1m2/g and an average pore size of8.7nm.2.The self-made mesoporous TiO₂ was modified with polyethyleneimine.Then the experiment was designed to investigate the effect of nanometer TiO₂,self-made mesoporous TiO₂ and mesoporous TiO₂ modified with PEI?meso-TiO₂/PEI?on the corrosion resistance of pure epoxy coating.From the AC impedance test of Shanghai Chen Hua CHI600 E electrochemical work station and Zview software fitting,it is found that the meso-TiO₂/PEI can improve the anti-corrosive performance of the coatings obviously.With 10 g waterborne epoxy resin,4g waterborne epoxy curing agent,3g water and 0.2g meso-TiO₂/PEI,the coating resistance Rc reaches 807.7?·cm2.The effect of meso-TiO₂/PEI addition on the properties of pure epoxy coating was investigated.At the same experimental conditions,the optimum content of meso-TiO₂/PEI was 0.5g.The mechanism of corrosion resistance of pure epoxy coating filled with the meso-TiO₂/PEI was analyzed from the perspective of crosslinking mechanism and diffusion path of corrosive medium.3.The anti-corrosion coating of vinyl acetate-acrylate emulsion modified with water-borne epoxy was prepared.The water based vinyl acetate-acrylate emulsion anti-corrosion coating was prepared,firstly.The effects of the proportion of the emulsion and water,the dosage of iron oxide red,the dosage of sodium hexametaphosphate,the dosage of eco-friendly anti-corrosive pigments and the dosage of the thickener RM8 W on the properties of the coatings wereinvestigated.It is found that the performance of the coating is optimal when the ratio of the emulsion to water is 15:8,the dosage of ferric oxide red is 2.5g,the dosage of six sodium polyphosphate is 0.04 g,the dosage of eco-friendly anti-corrosive pigments is 0.4g and the dosage of thickener RM8 W is 0.5g.The adhensive strength of anti-corrosive coating is the level of 4,and its salt spray resistance is 72 h,showing defective performance.Vinyl acetate-acrylate emulsion was modified with waterborne epoxy.The anti-corrosive performance of the emulsion was improved obviously with the waterborne epoxy.When the amount of waterborne epoxy resin is 11 g,the adhensive strength of the anti-corrosive coating reaches the level of 1 and the coating resistance to salt spray reaches 5 days.The effect of the self-made meso-TiO₂/PEI dosage on the performance of waterborne epoxy modified vinyl acetate-acrylate emulsion anticorrosion coating was investigated.The anti-corrosive performance of the coatings was improved obviously with the filling of meso-TiO₂/PEI.When the addition of meso-TiO₂ is 1.0g,the coating resistance to salt spray reaches 8 days.