| Corrosion and protection of steel have a long history,and it is of great significance.With the upgrading of state-to-business VOCs emission control,it is imperative that water-based coatings replace traditional solvent-based coatings for corrosion protection.However,the oil casing protective coating also requires the coating to be transparent,impact-resistant,fast-curing,etc.,and the water-based resin alone can not meet the requirements of anti-corrosion performance.This paper focuses on the above issues,mainly carried out the study of impact of the zinc phosphate and polyaniline particles on the anti-corrosion performance of the water-based resin,the main content and results are as follows:(1)Zinc phosphate(ZP)particles were prepared by liquid-phase metathesis.The effects of different reaction conditions on the morphology and particle size of the product were investigated.When the reaction temperature was 60?,the solution pH was 7,the zinc ion concentration was 0.3 M,and PEG-10000 was not added,the zinc phosphate particle size was 10 ?m and it was in the form of flakes.The ZP particles thus prepared were dispersed in an aqueous epoxy resin(ER),and when the amount of ZP added was 50.0 wt.%,the corrosion resistance of the coating was the best.(2)Polyaniline(PANI)particles were synthesized by chemical oxidation polymerization and the corrosion resistance of different polyaniline ER coatings was explored.The results showed that the anti-corrosion performance of PANI particles was significantly higher than that of ZP.The ER coating with 5.0 wt.%PANI added had the highest resistance and stability,and the best barrier properties;the ER coatings with 7.0 wt.%and 10.0 wt.%PANI added have stronger chemical capabilities,fewer coating defects,and better salt spray resistance.(3)The zinc phosphate-polyaniline composite(ZP-PANI)particles were prepared by adding zinc phosphate in the system of chemically oxidative polymerization to synthesize polyaniline,and the influence of different content of composite particles on the corrosion resistance of the coating was studied.The results show that the coating impedance increases with the addition of ZP-PANI.When the amount of ZP-PANI is increased to 7.0 wt.%,the barrier properties and stability of the coating increase significantly.The ER coating with 30.7 wt.%ZP-PANI added has the highest barrier,stability,and passivation capabilities,with resistance values on the order of 1010?·cm2,which is much higher than the impedance value of ER coatings adding zinc phosphate or polyaniline only.However,the mechanical properties and salt spray test results show that the ER coating with excessively high composite particle content has poor flexibility and adhesion,becomes more easy to blister or even fall off,and has poor resistance to salt spray. |
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