Synthesis Of The Polymer Emulsifier And Its Application In The Emulsion Polymerization Of Acrylate

Because of the specialty of its molecular structure, the amphiphilic polymer has a lot of characteristics. The random amphiphilic polymer was one kind of amphiphilic copolymers. They were easier prepared and had its special features as emulsifiers,dispersants,viscosity increasers,surfactants and so on in many industrial fields.Now, to get an amphiphilic polymer with high molecular weight and low surface tension, to study its application as emulsifiers and dispersants in emulsion polymerization is the hotspot of this field.In this paper, the amphiphilic copolymer poly(MAA-SMA-PEGMA) had been synthesized by the conventional free-radical copolymerization of methacrylic acid(MAA), stearyl acryate(SMA) and poly(ethylene glycol) methacrylate(PEGMA) monomers.The structure,critical micelle concentration (CMC) and surface tension of the copolymer were investigated. In addition, the mixture of the polymer surfactant and the small molecular surfactant was discussed. The results showed that the surface tension and CMC of mixture decreased dramatically at molar ratio of 5∶5.Then, the polymeric surfactant and its mixture system had been used as emulsifiers in the emulsion polymerization of acrylate. Acrylate polymer emulsion was prepared with pre-emulsified semi-continuous seeded emulsion polymerization technology. A proper quantity of functional and active crosslinking monomer was added during the course of emulsion polymerization, and water-resistant monomer was added into the acrylate emulsion. The experimental results show that added functional monomer and adopted polymerization technology improve polymerization stability greatly, and that added active crosslinking monomer and water-resistant monomer improve durability and water resistance of polymer emulsion. Emulsifiers were one of main factors which influence on the emulsion polymerization process. The mixed emulsifiers that influence on the polymerization stability and property of polymer emulsion including average particle size, stability of emulsion and viscosity were studied. Acrylate polymer emulsion was prepared with semi-continuous seeded emulsion polymerization. During the course of polymerization, mass of mixed emulsifiers and ratio of polymer surfactant and the small molecular surfactant were changed. The experimental results show that as emulsifiers increase, polymerization stability is improved and average particle size of emulsion decreased, and stability of emulsion increased, and viscosity are raised. Integrative properties of emulsion were the best when the ratio was 5∶5.