| Two-component ambient-cured waterborne epoxy coatings system is an environmental friendly polymer with low organic solvent content, lessmell, corrosion resistance and so on. It can be applied in many areaas. Waterborne epoxy curatives are the key of waterborne epoxy resin's application. The problems brought out by the synthesis of waterborne epoxy curatives are more complicated and harder than waterborne epoxy resin perse. A new self-emulsifying waterborne epoxy latex developed by China Petrochemical Group and Baling Petrochemical Company Limited. At present, there are no preferable waterborne curing agent come forth.In this research, a waterborne epoxy curing agent dispersoid was synthesized by using diglycidyl ether of polyglycol (PEG), triethylenetetramine and epoxy resin as raw materials. Emulsifier is the critical factor for preparing waterborne epoxy curing agent dispersoid. Emulsifier was synthesized by nucleophilic addition reaction between epoxy resin and PEG. The molecule structure of the emulsifier, especially the hydrophilic polyglycol group, has an important effect on emulsion properties, and the oleophylic group is also influential. The epichlorohydrin of process, including mole ratio of reaction materials, reaction temperature and reaction time, influence on the conversion rate of epoxy groups have been discussed. In order to incorporate the epoxy resin molecular chain segment into the molecular structure of curing agent to achieve the effect of"like dissolves like", was used as the chain extender to react with.Content of emulsion and the influences of reaction temperature and reaction time on the epoxy conversion of epoxy were discussed. Finally, at 50~60°C distilled water wascontinuously added to the emulsion until water content becomes 60%. The structure of the products was characterized by Fourier Transform Infrared Spectroscopy (FTIR), and the degradation of cured film was studied through thermogravimetry (TG). |
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