Preparation Of Waterborne Epoxy Resin Emulsion

Epoxy resin is widely applied to the bonding of a variety of metallic andnonmetallic materials, corrosion-resistant coatings, electrical insulating materials,composite materialsand other manufacturing for its excellent adhesion, corrosionresistance, stability, insulation and mechanical strength properties. Epoxy resin isused as sticky liquid or solid, insoluble in water, soluble in organic solvents. Mostorganic solvents are high volatile, toxic, inflammable and explosive, so theapplication of epoxy resin has been limited. With the awareness of environmentalprotection been heightened, water-based epoxy resin with water as solvent anddispersion medium more and more attention. Water is a cheap solvent ofenvironmental protection. It makes the use of the epoxy resin is more environmentalprotection, also for the use of epoxy resin reduced the cost. So waterborne epoxyresin research has great significance.This paper mainly introduces the hydrophilic carboxylic group was induced intothe main chain of the bisphenol-A-type epoxy resin via alcoholysis reaction betweenthe maleic anhydride and the secondary hydroxyl group of the bisphenol-A-typeepoxy resin. Then a self-emulsifying type aqueous epoxy resin was developed. Thechemical structure of the resultant was analyzed by FT-IR. The effects of temperature,time, ratio of reactants and neutralization temperature on the reaction were discussed.Then the optimum reaction condition was determined through orthogonal experimentdesign.The synthesized waterborne epoxy resin has favorable stability and water-dispersion.Experimental results indicated that using n-butyl acetate as solvent, at130℃for4h, mmaleic anhydride:mE-44=8.5:100, the waterborne epoxy resin with good waterdispersibility and good stability is synthesized, of which the ratio of the grafthydroxyl group(β) is86.51%and the ratio of remnant epoxy group(α) is96.44%, its average particle size is210nm, when the solid content is greater than or equal to30wt%, the storage stability is more than3months on room temperature.