Improved Synthesis of Linear Poly(ethylenimine) via Low-Temperature Polymerization of 2-Isopropyl-2-oxazoline in Chlorobenzene
Improved Synthesis of Linear Poly(ethylenimine) via Low-Temperature Polymerization of 2-Isopropyl-2-oxazoline in Chlorobenzene
复制标题
DOI：
10.1021/acs.macromol.5b00437
复制
发表时间：
2015-05-26
期刊：
影响因子：
5.5
通讯作者：
Steinke, Joachim H. G.
中科院分区：
文献类型：
--
作者：
Monnery, Bryn D.;Shaunak, Sunil;Steinke, Joachim H. G.
线性聚（乙烯亚胺）是一种阳离子聚合物，正在积极地进行基因治疗的临床试验。现有的合成方法产生相对宽的分子量分布。我们描述了一种改进的方法聚合2-烷基-2-恶唑啉作为一种路线，以线性聚（乙烯亚胺）。通过在低温（类似于42摄氏度）下使用非极性非干扰溶剂（氯苯），2-异丙基-2-恶唑啉的聚合比在乙腈中观察到的更快地进行，并且副反应少得多。1H-1 NMR观察表明，在传播中心（副自由离子在乙腈中），形成一个传播复合物的反应性比自由恶唑啉离子密切的离子配对。我们的研究结果表明，均匀或接近均匀（“单分散”）的聚合物可以合成与理论上可实现的泊松分布的名义偏差。
Linear poly(ethylenimine) is a cationic polymer that is actively being progressed into clinical trials for gene therapy. The existing synthetic methodology produces a relatively broad distribution of molecular weights. We describe an improved method of polymerizing 2-alkyl-2-oxazolines as a route to linear poly(ethylenimine). By using an apolar noninterfering solvent (chlorobenzene) at low temperature (similar to 42 degrees C), the polymerization of 2-isopropyl-2-oxazoline proceeds much more rapidly than is observed in acetonitrile, and with far fewer side reactions. H-1 NMR observations showed close ion pairing at the propagating center (vice free ions in acetonitrile) to form a propagating complex of greater reactivity than free oxazolinium ions. Our results indicate that uniform or near uniform ("monodisperse") polymers can be synthesized with nominal deviation from the theoretically achievable Poisson distributions.