Applied Research Of Polymerizable Emulsifiers In Acrylate Emulsion Polymerization

Acrylate emulsion has been paid much attention for its excellent performance and wide application. However, there are still many problems in the preparation of acrylate emulsion using conventional emulsifiers. In this paper we tried to prepare the acrylate emulsion through a type of polymerizable emulsifiers and the effects of the reaction conditions on emulsion polymerization were investigated. Polymerizable emulsifier of maleic acid ester with moderate reactivity were synthesized and their surface activity and emulsification properties were studied. The main contents of this thesis are as follows:1. The mechanism, progress and modification method of acrylate emulsion polymerization were reviewed briefly. The types, properties and applications in emulsion polymerization of polymerizable emulsifiers were introduced. It also provided a kind of design idea that using polymerizable emulsifier can solve the deficiency of traditional emulsifier and enhance the application functions of emulsion.2. Polyacrylate emulsions were synthesized using BA/MMA/AA as monomers, ammonium persulfate (APS) as initiator and ammonium sulfate allyoxy nonylphonoxy poly(ethyleneoxy)(10) ether (DNS-86) as emulsifier by seed semi-continuous emulsion polymerization. Effects of reactive temperature, the amount of initiator, the type of surfactants and the amount of DNS-86 on the properties of the emulsion and their films were discussed. The structures of the products were confirmed by FT-IR and the morphology and size were characterized by TEM. The results showed that the properties of the emulsion and films were improved using polymerizable emulsifier DNS-86. The ideal condition for the preparation of acrylate emulsion is that the concentration of DNS-86 is 4%, the concentration of the initiator is 0.4% and the temperature is 75℃.3. The emulsion of polyacrylate modified with y-(methacryloxy)propyl trimethoxy silane (KH-570) were prepared by seed semi-continuous emulsion polymerization. Effects of the amount of reactive monomer KH570 and DNS-86, reactive temperatures on the poproperties of the emulsion and films were discussed. The results indicate that the copolymer films possess excellent mechanical property.4. A new type of polymerizable emulsifier of sodium maleic monoalkyl polyoxyethylene propylsulfonate, which contained both anions and non-ions, was prepared by a three-step route. The structure were characterized by 1H NMR and FT-IR. Their CMC has been determined using Surface Tension Meter. The results demonstrated that the CMCs of those emulsifiers were much low. It was shown when the polymerizable emulsifier and traditional emulsifier sodium dodecyl sulfate(SDS) were used separately in semicontinuous polymerization of methyl methacrylate-butyl acrylate-acrylic, the high rate of conversion was observed in polymerizable emulsifier, meanwhile, electrolytic stability and water resistance of the synthesized emulsion were markedly improved.