| The sea area is facing the extreme marine environment,with high temperature,humidity,salinity,strong sunshine and other environmental characteristics.Traditional solvent-based zinc rich epoxy coatings(ZRECs)are widely used in industrial production due to their good corrosion resistance.It has unique anti-corrosion mechanisms,including cathodic protection,shielding and self-healing.However,in order to ensure the cathodic protection of the coatings,a large amount of zinc particles need to be added during the production process,which reduces the adhesion of the coating.In addition,the solvent-based ZRECs will volatilize a large amount of organic gas during use.With the enhancement of environmental awareness,organic solvents have received more restrictions during use.Therefore,more and more researchers have begun to develop waterborne ZRECs.In this paper,the formula of the basic anticorrosion system was determined by single factor experiment,and the effects of flake Zn powders,flake Zn Al alloy powders and flake Zn Al Mg alloy powders on the anti-corrosion performance of the coatings were studied.In view of the current situation that automated and intelligent deep-sea electronic equipment and facilities suffer from frequent failure of mold breeding,the use of four anti-mildew agents(4,5-dichloro-N-octyl-4-isothiazolin-3-one(DCOIT),2-n-octyl-4-isothiazolin-3-one(OIT),pyrithione(ZPT),3-iodo-2-propargylbutylcarbamate(IPBC))in epoxy system was studied,and a high-performance antifungal system was formed,which achieved the goal of broad-spectrum,high efficiency and high economy.Finally,the comprehensive matching and system integration of the anti-mildew system and the waterborne epoxy Zn Al anti-corrosive coating were carried out,and the anti-corrosion and anti-mildew integrated coating was formed and its anti-corrosion and anti-mildew mechanism was studied.The main research contents are as follows:1.In view of the severe corrosion of deep-sea equipment and facilities,the epoxy coating was redesigned.The results showed that when the coatings contained 21 wt%epoxy resin,1.5 wt%titanate coupling agent,1wt%organic bentonite,2 wt%mica powder,4 wt%talcum powder,57 wt%Zn Al alloy powders,1 wt%thickener,1 wt%defoamer,10.5 wt%curing agent,1 wt%film forming additive and 4 wt%talcum powders,the coating had best performance and could withstand salt spray for 960 h(The error range is within 1%).The epoxy coatings were prepared by using flake Zn powders,flake Zn Al alloy powders and flake Zn Al Mg alloy powders to replace the traditional spherical Zn powders.The results showed that the use of flake-like metal powders instead of spherical zinc pigments prolonged the penetration path of corrosive medium into the coatings and enhanced the physical shielding effect of the coatings.Among them,the Zn Al coatings has the best corrosion resistance,and the surface didn’t change after 28 days of salt spray.The initial impedance is 1.1×10~4Ω,which is higher than that of Zn Al Mg coatings and Zn coatings.2.The weather resistance,water resistance and heat resistance of four kinds of mildew inhibitors(DCOIT,OIT,ZPT,IPBC)in waterborne epoxy Zn Al coatings were systematically studied and analyzed,as well as the antibacterial effect on common molds(Aspergillus niger,Penicillium,Trichoderma viride,Aureobasidium pullulans)in marine environment.The results showed that the MIC value of OIT was the lowest,less than 10mg/kg.DCOIT,OIT,ZPT and IPBC had excellent weather resistance,heat resistance and water resistance.3.The anti-corrosion system and high-performance anti-mildew system of waterborne epoxy Zn Al coatings were integrated designed.The corrosion resistance of different metal powder coatings was compared,and the effect of the addition of anti-mildew agent OIT on the anti-corrosion and anti-mildew properties of the coatings were studied.The results showed that the salt spray resistance of Zn Al coatings and Zn Al@OIT coatings are better than that of Zn coatings.The addition of OIT doesn’t significantly reduce the impedance of the coatings,but improved the mildew resistance of the coatings.The obvious inhibition zone is formed in the mildew resistance test,and the mildew resistance grade of the coating is 0. |
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