title: Cu(II)-mediated atom transfer radical polymerization of methyl methacrylate via a strategy of thermo-regulated phase-separable catalysis in a liquid/liquid biphasic system: homogeneous catalysis, facile heterogeneous separation, and recycling.
abstract: A strategy of thermo-regulated phase-separable catalysis (TPSC) is applied to the Cu(II)-mediated atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) in a p-xylene/PEG-200 biphasic system. Initiators for continuous activator regeneration ATRP (ICAR ATRP) are used to establish the TPSC-based ICAR ATRP system using water-soluble TPMA as a ligand, EBPA as an initiator, CuBr2 as a catalyst, and AIBN as a reducing agent. By heating to 70 °C, unlimited miscibility of both solvents is achieved and the polymerization can be carried out under homogeneous conditions; then on cooling to 25 °C, the mixture separates into two phases again. As a result, the catalyst complex remains in the PEG-200 phase while the obtained polymers stay in the p-xylene phase. The catalyst can therefore be removed from the resultant polymers by easily separating the two different layers and can be reused again. It is important that well-defined PMMA with a controlled molecular weight and narrow molecular weight distribution could be obtained using this TPSC-based ICAR ATRP system.
authors.affiliation: Suzhou Key Laboratory of Macromolecular Design and Precision Synthesis, Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application, Department of Polymer Science and Engineering, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, 215123, China.
authors.forename: Jinlong
authors.initials: J
authors.lastname: Pan
authors.forename: Bingjie
authors.initials: B
authors.lastname: Zhang
authors.forename: Xiaowu
authors.initials: X
authors.lastname: Jiang
authors.forename: Lifen
authors.initials: L
authors.lastname: Zhang
authors.forename: Zhenping
authors.initials: Z
authors.lastname: Cheng
authors.forename: Xiulin
authors.initials: X
authors.lastname: Zhu
mesh_terms: D002384:Catalysis; D003300:Copper / Q000737:chemistry*; D007700:Kinetics; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D020366:Methylmethacrylate / Q000737:chemistry*; D008956:Models, Chemical; D008970:Molecular Weight; D011092:Polyethylene Glycols / Q000737:chemistry*; D058105:Polymerization; D012997:Solvents / Q000737:chemistry; D013696:Temperature; D014992:Xylenes / Q000737:chemistry*
chemical_list: D008024:Ligands; D012997:Solvents; D014992:Xylenes; C042514:cuprous ion; D020366:Methylmethacrylate; D011092:Polyethylene Glycols; C031286:4-xylene; D003300:Copper
keywords: ATRP; heterogeneous separation; homogeneous catalysis; recycling; thermo-regulated phase-separable catalysis (TPSC)