Study Of Atom Transfer Radical Polymerization Mediated By Iron～Ⅱ Chloride/Itaconic Acid

This paper is focused on the development of efficient catalyst system of free radical polymerization.In the research work of free radical polymerization, the development of new and efficient catalyst system is one of the main directions of it. Atom Transfer Radical Polymerization (ATRP) is a novel polymerization method promoted in the recent years. In the reaction of atom transfer radical polymerization, catalyst system plays a crucial role in the control of the polymerization, the development of novel and efficient catalyst system is in the highlight. 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. On the basis of literature research, we find that the differential of redox potential of the catalyst has a range for successive ATRP. Enlightened by this, we connect the selection of catalyst with electrochemistry. Ferrous (II) chloride/Itaconic was adopted as the catalyst for ATRP of styrene, and the effects of many factors on the polymerization were also investigated. Polystyrene with polydispersity index below 1.5 was obtained which elusive from conventional radical polymerization. The measured molecular weight linearly increases with the monomer conversation and the plot of ln([Mo]/[M]) versus time maintain linear. With these catalyst systems, the block copolymer was synthesized and measured. All these manifest that the chosen catalyst could catalyze the living/controlled polymerization of some monomer. In addition, the application of FeCl2/itaconic acid in ATRP also finds satisfactory results. Transitional metal complexed by acids prove to be effective in ATRP. The paper provide a roughly guideline in the design of catalyst. About the further relationship of the catalysis and the electrochemical properties was under study.For some characteristic groups in the macromolecules, whose reducing power isvery weak, the suitable oxidator is difficult to select in order to make graft copolymerization. Our studies indicate that the redox system, which composed of Ni(Ⅳ) or Cu(Ⅲ) and the weak reducing power group in the macromolecules (nylon, cellulose), could generate grafting point directly in the macromolecule and initiate high grafting efficiency copolymerization. High grafting efficiency copolymer was obtained. It is a new initiator system then others for that the graft copolymerization is carried out on the mild condition of 35℃ of alkaline medium, which is suitable for solution and swelling of cellulose. So, this initiator system is valuable and open up broad prospects for use.