| Two-component waterborne epoxy resin coating cured at room temperature wasinvestigated in this paper. The paper was divided into two parts. The first part wasabout the examination of the non-ionic water-based epoxy resin emulsion, the otherwas the preparation and characterization of its curing agents used at roomtemperature.The modification of epoxy resin played an important role in the pait-manufacturing for two-component waterborne epoxy resin coating cured at roomtemperature. A new method of preparing the non-ionic water-based epoxy emulsionwas studied. Firstly, an emulsifier was prepared with epoxy resin, one aminoteminated polyether and polyethylene glycol diglycidyl ether. Secondly, theemulsifier, epoxy resin and epoxy diluent were mixed together. At last, the water wasdropped under high shear and the non-ionic aqueous emulsion of epoxy resin wasprepared by the phase inversion processing. The best reaction condition was obtainedby IR and other methods. And the influences on the stability of waterborne epoxyemulsion and coating properties were investigated. The results showed that the bestconditions were as follows: the molar ratio of epoxy and amine hydrogen was2︰1,the content of polyethylene glycol diglycidyl ether in epoxy resin was between50%to60%and the best one amino-teminated polyether was M-2070. The epoxy resincoating had good coating properties when the amount of epoxy resin emulsifier wasbetween14%and18%.There were many drawbacks for the traditional curing agent in two-componentwaterborne epoxy coating cured at room temperature, such as toxicity, the short potpife, poor compatibility with epoxy resin and so on. As for the drawbacks, a newmethod of preparing the non-ionic water-based epoxy resin agent was studied. Firstly,an intermediate was prepared with liquid epoxy resin, polypropylene glycol diglycidylether, bisphenol A under the catalyst. Secondly, the reaction was done between theintermediate with amines, the excess amines and solvent were removed through thevacuum distillation. Finally, the resin was cool and the deionized water was dropped,an amber or pale yellow non-ionic waterborn epoxy resin curing agent cured at roomtemperature was obtained. The best reaction conditions for curing agent were obtainedby IR, particle size analysis, scanning electron microscopy and other methods. Andthe emulsifying ability of curing agent, corrosion resistance and coating curing kinetics were studied. The results showed that the epoxy coating had good coatingproperties when the molar ratio of polyethylene glycol diglycidyl and epoxy resin was1.2︰1and the reaction extent of bisphenol A was60%. The electrochemicalimpedance value was107.8. The apparent activation energy of waterborne epoxycuring reaction was44.06kJ/mol. |
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