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Miniemulsion ARGET ATRP via Interfacial and Ion-Pair Catalysis: From ppm to ppb of Residual Copper
Macromolecules ( IF 5.1 ) Pub Date : 2017-11-03 00:00:00 , DOI: 10.1021/acs.macromol.7b01730
Yi Wang 1 , Francesca Lorandi 1, 2 , Marco Fantin 1 , Paweł Chmielarz 1, 3 , Abdirisak A Isse 2 , Armando Gennaro 2 , Krzysztof Matyjaszewski 1
Affiliation  

It was recently reported that copper catalysts used in atom transfer radical polymerization (ATRP) can combine with anionic surfactants used in emulsion polymerization to form ion pairs. The ion pairs predominately reside at the surface of the monomer droplets, but they can also migrate inside the droplets and induce a controlled polymerization. This concept was applied to activator regenerated by electron transfer (ARGET) ATRP, with ascorbic acid as reducing agent. ATRP of n-butyl acrylate (BA) and n-butyl methacrylate (BMA) was carried out in miniemulsion using CuII/tris(2-pyridylmethyl)amine (TPMA) as catalyst, with several anionic surfactants forming the reactive ion-pair complexes. The amount and structure of surfactant controlled both the polymerization rate and the final particle size. Well-controlled polymers were prepared with catalyst loadings as low as 50 ppm, leaving only 300 ppb of Cu in the precipitated polymer. Efficient chain extension of a poly(BMA)-Br macroinitiator confirmed high retention of chain-end functionality. This procedure was exploited to prepare polymers with complex architectures such as block copolymers, star polymers, and molecular brushes.

中文翻译:


通过界面和离子对催化的细乳液 ARGET ATRP:残留铜从 ppm 到 ppb



最近有报道称,原子转移自由基聚合(ATRP)中使用的铜催化剂可以与乳液聚合中使用的阴离子表面活性剂结合形成离子对。离子对主要驻留在单体液滴的表面,但它们也可以迁移到液滴内部并引发受控聚合。这一概念被应用于以抗坏血酸为还原剂的电子转移再生活化剂(ARGET)ATRP。以Cu II /三(2-吡啶甲基)胺(TPMA)为催化剂,在细乳液中对丙烯酸正丁酯(BA)和甲基丙烯酸正丁酯(BMA)进行ATRP,多种阴离子表面活性剂形成反应性离子对配合物。表面活性剂的量和结构控制聚合速率和最终颗粒尺寸。使用低至 50 ppm 的催化剂负载制备出控制良好的聚合物,沉淀聚合物中仅留下 300 ppb 的 Cu。聚 (BMA)-Br 大分子引发剂的有效扩链证实了链端功能的高度保留。该过程用于制备具有复杂结构的聚合物,例如嵌段共聚物、星形聚合物和分子刷。
更新日期:2017-11-03
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