Preparation Of Modified F-51 Water-based Epoxy, Curing, And Performance Research

In this paper, preparation waterborne epoxy resin, the condition of the synthetic reaction was determined, study curing identity, and apply to composite material.According to the molecule design, a kind of modified resin which have both epoxy groups and hydrophilic groups was synthesized from polyfunctional group novolac epoxy resin (F-51) and diethanolamine. After neutralized by acid, the modified epoxy resin could dispersed into water and a waterborne epoxy resin system with excellent stability was produced. The effects of the reaction temperature and reaction time was studied and the optimum condition of the synthetic reaction was determined. During the process of the experiments, in order to make the modified resin got a good balance of reactivity and hydrophilicity, the relatively content of epoxy groups and hydrophilic groups in the modified resin was adjusted by changing the dosage of diethanolamine.The curing performance of the waterborne epoxy resin system was studied. It was showed that many epoxy curing agents which be dissolvable in water such as dicyandiamide, imidazole, TTA can be used in the system, emphasesly compare solvation, reaction and coating performance. Especially , the curing system which was made from the waterborne system and dicyandiamide had a long pot life that more than six months, a lower starting curing temperature which was 80 ℃. The optimum curing technics was determined by DSC and cross-linking experiments. The Tg of the cured product was 73.3℃.During the process of the experiments, in order to make the modified resin got a good curing performance, the modification resin was add to E-51, determined the dosage of E-51 is 50%,adopted intermisly adding water, modified resin/E-51 was gained, relatively content of epoxy groups and hydrophilic groups in the modified resin was adjusted by changing the dosage of diethanolamine.The application of thewaterborne epoxy resin system in the areas of composite was studied basically. The result showed, the shear strength of modified resin is 27.2MPa, and bending strength is 309MPa ;adopt modified resin/E-51 as composite material basal body, shear strength of composite material laminated sheet is 27.5MPa,and bending strength is 390MPa; it has good retain rate of mechanical property.