Controlled dispersion polymerization of methyl methacrylate in supercritical carbon dioxide via RAFT
Controlled dispersion polymerization of methyl methacrylate in supercritical carbon dioxide via RAFT
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DOI：
10.1021/ma702017r
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发表时间：
2008-02-26
期刊：
影响因子：
5.5
通讯作者：
Howdle, Steven M.
中科院分区：
文献类型：
--
作者：
Gregory, Andrew M.;Thurecht, Kristofer J.;Howdle, Steven M.
我们提出了一个全面的研究甲基丙烯酸甲酯（MMA）在超临界二氧化碳（scCO（2））中的控制分散聚合，利用可逆加成断裂链转移（RAFT）聚合，以产生活性微粒。这些微粒显示出受控的分子量演变、低的多分散性（PDI < 1.20）和良好限定的球形形态（直径约1.5 μ m）。1.40μ m）。考察了四种链转移剂的稳定基团（Z基团）和离去基团（R基团）的修饰。我们研究了它们对scCO中所得聚合物产物的分子量演变和形态的影响（2）。许多RAFT反应固有的速率阻滞效应提供了良好的动力学控制，其结果比在传统有机介质中进行的类似溶液聚合中观察到的要大得多。这被认为是由于在scCO（2）中RAFT机制和分散机制的组合。
We present a comprehensive investigation of the controlled dispersion polymerization of methyl methacrylate (MMA) in supercritical carbon dioxide (scCO(2)) utilizing reversible addition fragmentation chain transfer (RAFT) polymerization to produce living microparticles. These microparticles show controlled molecular weight evolution, low polydispersities (PDI < 1.20), and well-defined spherical morphology (diameter ca. 1.40 mu m). Four chain transfer agents are examined with modifications to both the stabilizing group (Z group) and leaving group (R group). We investigated their impact on molecular weight evolution and the morphology of the resulting polymer products in scCO(2). The rate retardation effect intrinsic to many RAFT reactions which provides good kinetic control Was shown to be much larger than that observed in analogous solution polymerizations performed in conventional organic media. This is believed to be due to the combination of the RAFT mechanism and the dispersion mechanism in scCO(2).