Study On Waterborne Epoxy Resin And It’s Curing

With the people’s increasing requirements to the safety and environment, solvent is becoming replaced by the waterborne system with the lower VOC which becomes more and more popular, due to many potential safety hazard and adverse to human beings. In the adhesive, paint epoxy resin has excellent physical and chemical properties.This article mainly studies the waterborne epoxy resin and its curing characteristics.Emulsifier preparation technology is the key to the resin emulsion preparation. Study shows that, when the molar ratio of polyethylene glycol 4000 and the epoxy resin(E44) is 1:1,and the reaction temperature is 190 ℃,and the reaction time is 3 hours,and using potassium persulfate as catalyst, block copolymer average molecular weight is about 70000, HLB value of 15.5 or so and the block copolymer has the best performance.When doing single factor experiment about emulsification we find emulsification effect was best when the emulsifier content was 15%, the water holdup was 23%,the phase inversion temperature was 60 ℃, the agitation speed was 700 r/min. Emulsion viscosity was 25.6 mPa·S, and D50 in size is 0.37 microns.Etherified amino resin is a kind of common resin curing agent. Studies of the preparation process of the curing agent show that the best processing technology is that in the hydroxyl methylation stage of melamine the molar ratio of melamine and formaldehyde is 1:7, heating temperature is 65 ℃with heating 12 minutes, and pH = 9. Etherification process has excellent performance when the molar ratio of alcohol and melamine is 8:1, with heating temperature of 55 ℃, heating time 90 min, and pH =5. The preparation of waterborne curing agent has low free formaldehyde content, and the etherification level is higher.Epoxy resin has low using value, only when getting with the curing agent we can get various useful properties of cured product. Compound epoxy emulsion with etherification polyhydroxyl-melamine and cure film, then test film-forming performance. By testing the film performance we found when the mass ratio of the two kinds of solution is 1:1, the curing temperature is 220 ℃, and time is 20 mins with DMF as catalyst,the film’s performance is best.Based on the optimal film technology test the curing kinetics.measured by the thermodynamic test and use the dynamics equations we get the activation energy Ea = 86.2 kJ/mol, frequency factor A = 2.8 x 1011 / s, the reaction order n = 0.93. Reaction kinetics provides a theoretical guidance for curing processing technology.