Cyclic alkoxyamine‐initiator tethered by azide/alkyne‐“click”‐chemistry enabling ring‐expansion vinyl polymerization providing macrocyclic polymers
Cyclic alkoxyamine‐initiator tethered by azide/alkyne‐“click”‐chemistry enabling ring‐expansion vinyl polymerization providing macrocyclic polymers
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DOI：
10.1002/pola.24126
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发表时间：
2010-08
期刊：
影响因子：
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通讯作者：
A. Narumi;Sylvia Zeidler;Haitham Barqawi;Claudia Enders;W. Binder
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文献类型：
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作者：
A. Narumi;Sylvia Zeidler;Haitham Barqawi;Claudia Enders;W. Binder
氮氧化物介导的可控自由基聚合(NMP)的环状引发剂是通过扩环乙烯基聚合反应制备大环聚合物的有力工具。为此，我们制备了一种霍克型NMP引发剂，该引发剂包括叠氮化物和末端炔作为无环前体，然后通过分子内叠氮/炔的“点击”反应将其拴在一起，生成最终的环状NMP引发剂。用凝胶渗透色谱(GPC)和基质辅助激光解吸电离飞行时间质谱仪(MALDI-TOF MS)对聚合物进行了表征。这些结果证明，苯乙烯的扩环聚合与自由基环交叉反应一起发生，这些反应源于生成具有较高膨胀环的大环聚苯乙烯的固有氮氧化物的交换。
A cyclic initiator for the nitroxide-mediated controlled radical polymerization (NMP) is a powerful tool for the preparation of macrocyclic polymers via a ring-expansion vinyl polymerization mechanism. For this purpose, we prepared a Hawker-type NMP-initiator that includes an azide and a terminal alkyne as an acyclic precursor, which is subsequently tethered via an intramolecular azide/alkyne-"click"-reaction, producing the final cyclic NMP-initiator. The polymerization reactions of styrene with cyclic initiator were demonstrated and the resultant polymers were characterized by the gel permeation chromatography (GPC) and the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). These results prove that the ring-expansion polymerization of styrene occurred together with the radical ring-crossover reactions originating from the exchange of the inherent nitroxides generating macrocyclic polystyrenes with higher expanded rings.