Study Of Atom Transfer Radical Polymerization Mediated By Ferrous-based Catalyst

This paper is divided into two parts.The first part is focused on the study of Atom Transfer Radical Polymerization (ATRP) mediated by ferrous-based catalyst.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, the selection of catalyst is generally by trial and error method. Also 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/EDTA and Ferrous (II) chloride/H2O were 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([M0]/[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 FeCl2/7-Hydroxy-4-methyl coumarin, FeCb/itaconic acid in ATRP also finds satisfactory results. Transitional metal complexed by acids prove to be effective in ATRP. The paper provide a roughlyIIguideline in the design of catalyst. About the further relationship of the catalysis and theelectrochemical properties was under study.The second part is about the graft copolymerization redox initiated by theultra-valence transitional metal potassium diperiodatonickelate(IV) peiodate complex (DPN).Ni (IV) was employed as oxidant and natural polymers (casein, chitosan) as reductant to make up the redox system to initiate the grafting polymerization. High grafting efficiency copolymer was obtained. The combined effects of the principal reaction variables on the copolymerization were investigated and the application was probed.