Study On Reverse Atom Transfer Radical Emulsion Polymerization Of Styrene/Butyl Acrylate

In the reaction of reverse atom transfer radical polymerization(RATRP), catalyst system palys a very important role in the control of polymerization, one of the developments of novel and efficient catalyst system is in the highlight. Generally, the selection of catalyst is by trial and error method, in the literature documented home and abroad. It is believed that acids may deactivate the metal organic catalyst, resulting in poor control of the polymerization. It found that the differential of redox potential of the catalyst had a range for successive RATRP on the basis of research. So ferric (III) chloride/EDTA was adopted as the catalyst system for RATRP emulsion polymerization of styrene/butyl acrylate. It was expected to make it true that the polymers could be controlled.In this paper, we used styrene (St) and butyl acrylic (BA) as monomers, synthesized St/BA random copolymers through emulsion RATRP, and with controlled was prepared. We had researched the various factors influencing the polymerization process compared with emulsion polymerization.By measuring the conversion of reaction, molecular weight and polydispersity, the RATRP of styrene/butyl acrylic in emulsion was studied. The effects of the ratio of monomers, initiators, reaction temperature, emulsifier and other factors were investigated, respectively. The results show that:using ferric (Ⅲ) chloride/EDTA/azodiisobutyronitrile (AIBN) as the catalyst system, polymers with polydispersity (PDI=1.40) was obtained at the ratio of200/1/4/2([monomers]0/[AIBN]o/[FeCl3·6H2O]0/[EDTA]0), Tween80as surfactant and the proper reaction temperature is80℃. The measured molecular weight linearly increases with the conversion and the plot of ln([M]o/[M]) versus time maintain linear. The structure of random polymers was analyzed by IR and1H-NMR. The result shows that there was a chlorine group on the copolymer chains. The results of compared with emulsion polymerization by Zetasizer Nano ZS90and DSC shows that the average particle(135.9nm) with iron/EDTA as the catalyst system was wider than that with emulsion polymerization, the glass transition temperature(Tg) was about17.5℃by those emulsion polymerization.In the paper, low toxic catalytic system and transitional metal complexed by EDTA prove to be effective in RATRP emulsion on the one hand, the reaearch founder the functional polymer to realistic product and provided a roughly in the controlled of catalyst.