Preparation And Properties Of Water-borne Zinc-rich Epoxy Primer

The research contents of this thesis is water-borne zinc-rich epoxy primer,mainly divided into two parts:The first part is the preparation and properties of water-borne epoxy resin curing agent;The second part is the preparation and characterization of water-borne zinc-rich epoxy primer.Water-borne epoxy resin curing agent as a necessary component of a two-component water-borne epoxy resin coating and its research is of great significance.In order to solve the disadvantages of current water-borne epoxy resin curing agent,this paper studied a method to preparation of a new type of environmentally friendly water-borne epoxy resin curing agent.This method first uses polyether amine chain extension reaction with mixture of epoxy resin and polypropylene glycol diglycidyl ether preparation of intermediate.Then use the intermediates with multiple amine chain extension reaction,preparing an amine-capped epoxy-amine adduct.Last dropwise addition of deionized water mechanical dispersion obtained as a yellow transparent water-borne epoxy resin curing agent.Through IR testing,amine and epoxy group conversion testing to determine the conditions of the synthesis of the curing agent.At the same time,through the coating performance testing research on the technological formula for the curing agent,so as to determine the best formula.Finally,through the electrochemical test,particle size test and differential scanning calorimetry to discuss the anti-corrosion performance of the curing agent,emulsification properties and curing kinetics.Results show that the Epon828/PPGDGE mole ratio is 1:1.2,ED-600 theory extender chain degree is 5%,TETA/intermediates mole ratio is 4.4:1,curing agent performance was best.The apparent activation energy of the curing agent is 38.43 KJ/mol,curing reaction is a complex reaction,The curing agent must be cured film at a certain temperature in order to obtain the best performance.In view of the present three component solvent zinc-rich epoxy primer high VOC content,construction difficulty,high cost and so on,this paper studies a kind of environmental friendly,convenient construction of two-component water-borne zinc-rich epoxy primer.This method will first fillers and various additives evenly dispersed in ethanol as the solvent of water-borne epoxy resin curing agent,preparation of a kind of stable compounds containing zinc water-borne epoxy resin curing agent(Part A).By the solvent precipitation rate and the high speed centrifugal test,the stability of zinc powder in water-borne epoxy resin curing agent were studied,preparation of the stability of Part A.Part A and water-borne epoxy emulsion will according to the equivalent mechanical blending,curing use after a period of time.Through electrochemical analysis,to the zinc powder particle size,shape,content,and of different fillers on the effects on the anticorrosive properties of the water-borne zinc-rich epoxy primer were studied.Through water absorption test,mechanical property and corrosion resistance test further validation content of zinc powder and fillers on the properties of coating effect,so as to determine the best water-borne zinc-rich epoxy primer formula.Finally through electron microscopy(SEM)and thermogravimetric analysis(TG)of water-borne zinc-rich epoxy primer surface morphology and heat resistance were studied.The results show that the appropriate to add organic bentonite can improve the stability of zinc powder in curing agent.Choose size for 4?m spherical and ellipsoidal mixed zinc powder,adding amount of 75%-80%of water-borne zinc-rich epoxy primer comprehensive performance better.Composite filler added is effective to improve the anticorrosive properties of the primer.At the same time,the primer surface morphology and thermal stability is better.