Zero‐valent bimetallic iron/copper catalyzed SET‐LRP: A dual activation by zero‐valent iron
Zero‐valent bimetallic iron/copper catalyzed SET‐LRP: A dual activation by zero‐valent iron
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DOI：
10.1002/pola.25849
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发表时间：
2012-03
期刊：
影响因子：
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通讯作者：
Lili Zhou;Zhengbiao Zhang;Wen-Xia Wang;Zhenping Cheng;Nianchen Zhou;Jian Zhu;Wei Zhang-;Xiu-lin Zhu
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文献类型：
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作者：
Lili Zhou;Zhengbiao Zhang;Wen-Xia Wang;Zhenping Cheng;Nianchen Zhou;Jian Zhu;Wei Zhang-;Xiu-lin Zhu
在25 °C下，以Fe（0）和Cu（0）为催化剂，在二甲基亚砜中进行了甲基丙烯酸甲酯的单电子转移活性自由基聚合（SET-LRP）。探索了[Fe（0）]0/[Cu（0）]0（0/1.5、0.5/1、0.75/0.75、1/0.5和1.3/0.2）的不同进料比。随着Fe（0）投料量的增加，聚合速率略有下降，诱导期延长。而随着Fe（0）含量的增加，对分子量的控制得到改善。在[Fe（0）]0/[Cu（0）]0 = 1/0.5时实现最佳控制（引发效率= 91%）。Fe（0）与[Fe（0）]0：[Cu（0）]0 = 1.3：0.2的进料比的进一步增加导致不受控制的聚合。探索可用的溶剂和配体，这种聚合证实了SET-LRP机制。结果表明，Fe（0）在该过程中具有双重作用：一方面是Cu（0）的活化剂，有利于更好地控制分子量;另一方面是R-X或Pn-X的活化剂，可确保与Cu（0）相当的聚合速率。这项工作为SET-LRP提供了一种替代和经济的催化剂，并最终加强了SET-LRP技术。© 2011 Wiley Periodicals，Inc. J Polym Sci Part A：Polym Chem，2012
In this work, bimetallic zero-valent metal (Fe(0) powder and Cu(0) powder) was used to mediate the single electron transfer-living radical polymerization (SET-LRP) of methyl methacrylate at 25 °C in dimethyl sulfoxide. Different feed ratios of [Fe(0)]0/[Cu(0)]0 (0/1.5, 0.5/1, 0.75/0.75, 1/0.5, and 1.3/0.2) were explored. With the increase of Fe(0) feed, the polymerization rate was mildly depressed with a prolonged induction period. While, the control over the molecular weights was improved upon the increase of Fe(0). A best control (initiation efficiency = 91%) was achieved at [Fe(0)]0/[Cu(0)]0 = 1/0.5. A further increase of Fe(0) to the feed ratio of [Fe(0)]0:[Cu(0)]0 = 1.3: 0.2 led to a uncontrolled polymerization. Explorations of available solvents and ligands for this polymerization confirmed the SET-LRP mechanism. It was suggested that Fe(0) might act as a dual role in this process: one was the activation agent for Cu(0), which favored a better control over the molecular weights; The other was an alternative catalyst for the activation of R-X or Pn-X to generate radicals, which assured a comparable polymerization rate as that of Cu(0). This work provided an alternative and economical catalyst for SET-LRP, and would eventually reinforce the SET-LRP technique. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012