In-Depth LCCC-(GELC)-SEC Characterization of ABA Block Copolymers Generated by a Mechanistic Switch from RAFT to ROP
In-Depth LCCC-(GELC)-SEC Characterization of ABA Block Copolymers Generated by a Mechanistic Switch from RAFT to ROP
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DOI：
10.1021/ma2022452
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发表时间：
2012-01
期刊：
影响因子：
5.5
通讯作者：
Christina Schmid;S. Weidner;J. Falkenhagen;C. Barner‐Kowollik
中科院分区：
文献类型：
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作者：
Christina Schmid;S. Weidner;J. Falkenhagen;C. Barner‐Kowollik
介绍了一种从可逆加成-断裂链转移(RAFT)聚合到开环聚合(ROP)形成两嵌段共聚物的新方法，用于合成ABA(STAR)嵌段共聚物。合成步骤包括与R基团设计的RAFT试剂进行聚合，将硫代羰基硫代端基转化为羟基官能团，然后通过ROP对其进行扩链。用尺寸排斥色谱、核磁共振、红外光谱、基质辅助激光解吸电离等手段对得到的线型poly(e-caprolactone)-block-poly(styrene)-block-poly(e-caprolactone)(PCl-b-PS-b-PCl)(12500gmol-1≤Mn≤33000gmol-1)和星形聚苯乙烯-嵌段聚己内酯(Mn=36000gmol-1)共聚物进行了表征。目前的研究重点是通过多维结构表征ABA(STAR)嵌段聚合物。
A recently introduced procedure involving a mechanistic switch from reversible addition–fragmentation chain transfer (RAFT) polymerization to ring-opening polymerization (ROP) to form diblock copolymers is applied to synthesize ABA (star) block copolymers. The synthetic steps include the polymerization of styrene with R-group designed RAFT agents, the transformation of the thiocarbonyl thio end groups into OH functionalities, and their subsequent chain extension by ROP. The obtained linear ABA poly(e-caprolactone)-block-poly(styrene)-block-poly(e-caprolactone) (pCL-b-pS-b-pCL) (12 500 g mol–1 ≤ Mn ≤ 33 000 g mol–1) and the star-shaped poly(styrene)-block-poly(e-caprolactone) (Mn = 36 000 g mol–1) copolymers were analyzed by size exclusion chromatography (SEC), nuclear magnetic resonance (NMR), infrared (IR) spectroscopy, and matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. The focus of the current study is on the detailed characterization of the ABA (star) block polymers via multidim...