| Epoxy resin has been widely used as coatings, composites, adhesives and other fields because of its excellent mechanical properties, bond properties and process performance. Solvent-based epoxy resin coatings are currently used mostly, which leads to the serious environmental pollution. In recent years, water-based coatings are acclaimed because of thire safety, green, low VOC, etc. The epoxy resin emulsion which is modified with chemical method has small particle size, usually nm-class, and has good storage stability. And in this way, epoxy resin can be modified according to needs of different modified agent to accept unique properties, which is the focus of today's research and development.In this paper, waterborne epoxy resin emulsion was synthesized by graft copolymerization of MAA, BA, St reacting as grafting monomer, while the phosphate and organic siloxane played a role as functional monomer. The experimental results were characterized by Nano-particle size analyzer, FTIR, TEM, TG, DSC, AFM. The effects of the amount of every kind of monomer on the properties of the emulsion and film performance are assessed. The main tasks are as follows:1. Epoxy-acrylic emulsion is synthesized and the appropriate type of epoxy resin and solvent, the amount of monomer and dosage of initiator, the grafting reaction and neutralization temperature and the neutralization extent are determined to get emulsion with good water dispersion. The average particle size lower than 300nm and the solid content is 25-30%;2. Curing conditions, the proportion of hard and soft monomer on the properties of cured film has been evaluated;3. Phosphate PAM-200 is selected as a functional monomer to modify the epoxy-acrylic resin. It is found that the introduction of PAM-200 improved the performance of adhesion of the epoxy emulsion on metal substrate and the fabrication of large films. The optimal dosage of PAM is determined as 6%;4. Organic siloxane A-151 and A-172 are also selected as a functional monomer to modify the epoxy-acrylic resin. It is found that the flexibility, adhesion and impact strength of the cured film are better than the unmodified, while water absorption is decreased. The optimal dosage of siloxane is determined as 12%;5. The introduction of phosphate PAM-200 and Silicone A-172 into the epoxy-acrylic resin has been carried out. It could be concluded that the two monomers play their unique role respectively and do not conflict with each other. That makes up for the lack of separate modification and the cured films are with excellent properties;6. Curing agent is added into the modified emulsion to form a two-component system, and the curing temperature is determined at 160℃. The impact strength of cured film from 90kg-cm raised to 120kg-cm, which can be used in the areas with high requirements of the impact strength.
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