Dramatic acceleration of SET-LRP of methyl acrylate during catalysis with activated Cu(0) wire
Dramatic acceleration of SET-LRP of methyl acrylate during catalysis with activated Cu(0) wire
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DOI：
10.1002/pola.24309
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发表时间：
2010-11
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影响因子：
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通讯作者：
N. Nguyen;V. Percec
中科院分区：
文献类型：
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作者：
N. Nguyen;V. Percec
报道了一种简单的活化单电子转移活性自由基聚合（SET-LRP）催化剂Cu（0）丝的方法。在空气中储存的Cu（0）表面覆盖有一层CuO。已充分确定，CuO对于SET-LRP是比Cu（0）反应性更低的催化剂。我们在这里报告的Cu（0）线在氮气下的激活还原CuO从其表面的Cu（0）与水合肼的处理。在二甲基亚砜（DMSO）中，在25 °C下用活化的Cu（0）线催化的丙烯酸甲酯（MA）的SET-LRP的动力学证明了聚合的显著加速，并且在几个实验室中在用非活化的Cu（0）催化的SET-LRP期间观察到诱导期的缺失。将活化的Cu（0）线暴露于空气导致较低的表观传播速率常数，因为Cu（0）逐渐氧化成CuO。SET-LRP的这种显著加速类似于用商业Cu（0）纳米粉末观察到的加速，除了聚合提供优异的分子量演变、非常窄的分子量分布和高聚合物链端官能度。
A simple method for the activation of the Cu(0) wire used as catalyst in single-electron transfer living radical polymerization (SET-LRP) is reported. The surface of Cu(0) stored in air is coated with a layer of CuO. It is well established that CuO is a less reactive catalyst for SET-LRP than Cu(0). We report here the activation of the Cu(0) wire under nitrogen by the reduction of CuO from its surface to Cu(0) by treatment with hydrazine hydrate. The kinetics of SET-LRP of methyl acrylate (MA) catalyzed with activated Cu(0) wire in dimethyl sulfoxide (DMSO) at 25 °C demonstrated a dramatic acceleration of the polymerization and the absence of the induction period observed during SET-LRP catalyzed with nonactivated Cu(0) in several laboratories. Exposure of the activated Cu(0) wire to air results in a lower apparent rate constant of propagation because of gradual oxidation of Cu(0) to CuO. This dramatic acceleration of SET-LRP is similar to that observed with commercial Cu(0) nanopowder except that the polymerization provides excellent molecular weight evolution, very narrow molecular weight distribution and high polymer chain-end functionality.