Preparation And Modification Of The Novel Waterborne Epoxy Curing Agent

The preparation and modification of the waterborne epoxy curing agents is investigated in this paper. Part one is about the preparation of waterborne epoxy curing agents. Part two is about the preparation and modification of water-dispersible epoxy curing agent.Part one, the amine-terminated intermediate was prepared with epoxy resin (EPON828) and Triethylene-tetramine (TEDA). Then the epoxy-terminated polyalkylene glycol (650) was used as the chain extender to react with the amine-terminated intermediate. And finally the low viscosity water-solubility curing agent was gained by the amine-terminated curing agent capped with a monoepoxide. The reactive result has been characterized by FTIR and other methods. It was found that the amine-terminated intermediate was prepared with epoxy resin (EPON828) and Triethylene-tetramine (TEDA) in the molar ratio TETA / EPON828 2.3:1 ,at the 65℃reacting for 3 h, then the amine-terminated intermediate reacting with the epoxy-terminated polyalkylene glycol(650) in the molar ratio 650 / amine-terminated intermediate 0.6:1 ,at the 100℃reacting for 2 h. And finally the low viscosity water-solubility curing agent was gained by the amine-terminated curing agent capped with phenyl glycidyl ether. The cured film cured at room temperature has a good glossiness, hardness, adhesion and good resistance to impact. And based on the curing agent the formula of the waterborne epoxy anti-corrosive coating was made.Part two, a water-dispersible epoxy curing agent was prepared using phenyl glycidyl ether, m-Xylylenediamine (MXDA), reacting-emulsifiers and liquid epoxy resin (EPON828). The reacting-emulsifiers were synthesized using epoxy resin (EPON828) and polyoxyalkylene (PEG). The water-dispersible epoxy curing agent was prepared by phase inversion technique with water. And modification of water-dispersible epoxy curing agent was prepared using amine silicone (KH-550) as a modifier agent of the water-dispersible epoxy curing agent. The particle size distribution and stability of water-dispersible epoxy curing agent were effected by the molecular weight of PEG,the proportion between PEG6000 and epoxy, reacting-emulsifiers and amine silicone(KH-550). It was found that the best dispersion effect can be obtained using the reacting-emulsifiers synthesized by PEG6000 and EPON828 with equivalent molar ratio. The dispersion with 9 percent reacting-emulsifier concentration has the best stability. It's properties: the solid content58%,particle size826 nm, amine value119 mg KOH/g , viscidity 4500 mPa·s. Appropriate amine silicone improved the rigidity and glossiness of the cured film.