Study On Modification Of UV-CURED Waterborne Epoxy Resin

With the progress of the times, the environmental laws and people’s awareness of the health, safety, environmental protection and energy saving has improved steadily, the pollution-free environmentally friendly paint with low VOC or zero VOC received increasing attention. The research and development of UV-curable waterborne coatings has become the hot research of paint field and one of the new developing trend of the coatings industry.Epoxy resin(EP) has adhesion properties, low curing temperature, good blending performance and chemical stability, low cost, and has a wide use in the field of coatings, adhesives, composite materials. However, the toughness, impact resistance and thermal resistance of its film are poor, So to modify it becomes a hot topic. This paper used epoxidized soybean oil(ESO) and organosilicon to modify the EP, and finally obtained the environmentally friendly UV-curable epoxy resin system with good toughness, high heat resistance, making the toughness the thermal decomposition temperature of the resin film been greatly improved. The work of this paper can be divided into the following three parts:①The UV-curable waterborne epoxy resin is synthesized with epoxy resin, itaconic acid, acrylic and other materials, and catylists are also selected.The results showed that: When the reaction temperature was115℃, the mole ratio of acrylic and itaconic acid was1:1, using1%triphenylphosphine as the catalyst, hydroxyethyl methacrylate as a cosolvent, N, N-dimethyl ethanolamine as a neutralizer, the obtained water-based resin had good storage stability and the water resistance of the coating film lasted up to six months. And adjusting the mole ratio of itaconic acid and acrylic acid, you can adjust the alkali resistance of the coating.②The ESO modified EP was synthesized and the effect of the added quantity of the epoxidized soybean oil on the film was investigated. The results showed that:when the mass ratio of epoxidized soybean oil and epoxy resin was1:1, a relatively good performance coating could be obtained:the hardness was4H, elongation at break was52%, and the impact strength was greater than50kg·cm.③The organosilicon modified epoxy soybean oil-epoxy resin systems was synthesized, and the effect of silicone type, content and reaction temperature on the film was investigated. The experimental results showed that:when added quantity of methyl triethoxysilane was14.4%, the mass ratio of epoxidized soybean oil and epoxy resin wasl:2, the hardness of the film was3H, tensile strength was12.5Mpa, fracture elongation rate was62.3%, the impact strength was greater than50kg·cm, and the thermal decomposition temperature was414℃improved from391℃.