F-51 Epoxy Resin Waterborne Modified

The waterborne epoxy resin can be used without volatile oganic compound (VOC), meet the requirements of environment protection. Resent years, the study on the waterborne technologies of epoxy resin and its application have been a popular area which attract much attention.In this paper, 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. The reactive product was characterized by FTIR, the result show that the structure of the modified resin was just the form what was designed firstly. 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 DDM and so on can all be used in the system. 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℃The application of the waterborne epoxy resin system in the areas of coating and composite was studied basically. The result showed, the paint filmsobtained from the curing system of modified resin/dicyandiamide showed good properties in luster, adhersion, hardness, and also excellent performance on water-resistances and chemical resistance; The laminated glass cloth made of the waterborne epoxy curing system had good physical and mechanical properties, its shearing strength was 33.3MPa, flexural strength reached 502.9MPa.