Preparation of low molecular weight cyclic polystyrenes with high purity via liquid chromatography at the critical condition
Preparation of low molecular weight cyclic polystyrenes with high purity via liquid chromatography at the critical condition
复制标题
临界条件液相色谱法制备高纯度低分子量环状聚苯乙烯
DOI：
10.1016/j.polymer.2017.12.020
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发表时间：
2018
期刊：
影响因子：
4.6
通讯作者：
Chang Taihyun
中科院分区：
文献类型：
--
作者：
Gao Lingfeng;Oh Joongsuk;Tu Yingfeng;Chang Taihyun
由线性前体通过闭环方法合成的环状聚合物含有一些线性污染物。在这项工作中，通过临界条件液相色谱 (LCCC) 与基质辅助激光解吸/电离飞行时间质谱的耦合证明了环状聚苯乙烯 (c-PS) 中线性污染物的来源。通过链终止，线性污染物被揭示为 ATRP 过程中的“死”链、未反应的线性聚苯乙烯 (l-PS) 前体以及通过不完美的闭环反应形成的二聚体。通过LCCC分级纯化c-PS，结果表明对于低分子量(<10,000)PS，在c-PS的临界吸附点(CAP)处的LCCC分级比在线性的CAP处更有效。提出了一种两步 LCCC 方法，通过在 CAP ofl-PS 和 CAP ofc-PS 处进行串联 LCCC 分级来制备高纯度 (>99.6%) 的 c-PS。
Cyclic polymers synthesized by ring-closure method from linear precursors contain some of linear contaminates. In this work, the origin of linear contaminates in cyclic polystyrenes (c-PS) is demonstrated by the coupling of liquid chromatography at the critical condition (LCCC) with matrix-assisted laser desorption/ionization time-of-flight mass spectra. The linear contaminates are revealed to be the “dead” chains during ATRP by chain termination, the unreacted linear polystyrene (l-PS) precursors, and the dimers by the imperfect ring-closure reaction. Thec-PS are purified by LCCC fractionation, and the results show the LCCC fractionation at the critical adsorption point (CAP) ofc-PS is more efficient than that at the CAP of linears for low molecular weight (<10,000) PS. A two-step LCCC method is presented for the preparation ofc-PS with high purity (>99.6%) via the tandem-coupled LCCC fractionation at the CAP ofl-PS and at the CAP ofc-PS.