Xiaowu Jiang, Jian Wu, Lifen Zhang*（张丽芬）, Zhenping Cheng* （程振平）and Xiulin Zhu
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
Macromol. Rapid Commun. ,2016,37,143−148
How to simply and efficiently separate and recycle catalyst has still been a constraint for the wide application of atom transfer radical polymerization (ATRP), especially for the polymerization systems with hydrophilic monomers because the polar functional groups may coordinate with transition metal salts, resulting in abundant catalyst residual in the resultant water-soluble polymers. In order to overcome this problem, a latent-biphasic system is developed, which can be successfully used for ATRP catalyst separation and recycling in situ for various kinds of hydrophilic monomers for the first time, such as poly(ethylene glycol) monomethyl ether methacrylate (PEGMA), 2-hydroxyethyl methacrylate (HEMA), 2-(dimethylamino)ethyl methacrylate (DMAEMA), N,N-dimethyl acrylamide (DMA), and N-isopropylacrylamide (NIPAM). Herein, random copolymer of octadecyl acrylate (OA), MA-Ln (2-(bis(pyridin-2-ylmethyl)amino)ethyl acrylate), and POA-ran-P(MA-Ln) is designed as the macroligand, and heptane/ethanol is selected as the biphasic solvent. Copper(II) bromide (CuBr2) is employed as the catalyst, PEG-bound 2-bromo-2-methylpropanoate (PEG350-Br) as the water-soluble ATRP initiator and 2,2′-azobis(isobutyronitrile) (AIBN) as the azo-initiator to establish an ICAR (initiators for continuous activator regeneration) ATRP system. Importantly, well-defined water-soluble polymers are obtained even though the recyclable catalyst is used for sixth times.
链接：//onlinelibrary.wiley.com/doi/10.1002/marc.201500439/abstract
