Synthesis Of Poly(n-butyl Acrylate) Emulsion Via AGET ATRP

The atom transfer radical polymerization with the activator generated by electrontransfer (AGET ATRP) is one of the latest advances in ATRP techniques The transitionmetal oxide is used for catalysts and a reducing agent is added to improve theanti-oxidative capability of AGET ATRP system, which has been paid much attentionfrom the very beginning. Emulsion polymerization is a process with the water asdispersion medium. Therefore, it is an environment-friendly chemical process，whichis up to the needs of modern industrial development. In this paper, AGET ATRP wascombined with the traditional emulsion polymerization technology， and thepolybutylacrylate was prepared via AGET ATRP in emulsion by means of two-stepfeeding method. The polymerization was conducted with the n-butylacrylate (BA) asthe monomer, a ferric chloride hexahydrate (FeCl36H2O) as the catalyst, aN-hexadecyl ethylenediamine triacetic acid (HED3A) prepared in lab as the ligand，anascorbic acid (VC) as the reducing agent, a-bromoisobutyrate (EBiB) as the initiatorand a compound of cationic Gemini emulsifier (C16-2-16) and polyoxyethylene laurylether (Brij35) as the emulsifier. The main contents of this paper are as follows:Firstly, HED3A was synthesized with the ethanediamine and thebromohexadecane as raw materials and the influences of the raw material ratio,reaction temperature and pH value on the reaction process were studied. Thus, theoptimum reaction conditions were achieved with the molar ratio of chloroacetic acid toN-hexadecyl ethylenediamine of3.6, reaction temperature of60℃, and the pH valueof around8. In this case, the final product yield was82.7%. Furthermore, the structureof HED3A was characterized by Fourier transform infrared spectroscopy (FT-IR) andproton nuclear magnetic resonance spectroscopy (1HNMR). And it was indicated thatHED3A was synthetized successfully.Secondly, the effects of the feeding methods, the emulsifiers, the ligands, thecatalysts, the reducing agents, the initiator and the polymerization temperature on emulsion AGET ATRP of BA were investigated. The results demonstrated that thepolymerization showed good controllability when the material ratios of[BA]0/[FeCl3·6H2O]0/[HED3A]0/[VC]0/[EBiB]0=300/1/0.5/0.5/2, solid content was13wt%, ratio between Brij35and C16-2-16was3:1, the total emulsifiers content was4.0wt%(relative to monomer), and the reaction temperature was60℃. The conversionwas calculated by gravimetric analysis. And it is found that the conversion wasincreasing slowly over time, and the final monomer conversion was75.52%.Meanwhile, it presented a better linear relation between ln([M]0/[M]) and time. Inaddition, the structure of C16-2-16and PBA was characterized by FT-IR and1HNMR.The relative molecular weight (Mn=439416g mol-1) and the molecular weightdistribution index (PDI=1.27) as well as the glass transition temperature(Tg=-46.8℃)of polymers were detrmined by gel permeation chromatography (GPC) and differentialscanning calorimeter (DSC), respectively. And the particle morphology and particlesize distribution of the emulsion were characterized by the Transmission ElectronMicroscope (TEM) and Malvern Zetasizer (Nano ZS90), which showed that Z-averageparticle size of the emulsion was103.2nm and the particle size distribution index was0.030.