Experimental evidence and beneficial use of confined space effect in nitroxide-mediated radical microemulsion polymerization (microemulsion NMP) of n-butyl acrylate
Experimental evidence and beneficial use of confined space effect in nitroxide-mediated radical microemulsion polymerization (microemulsion NMP) of n-butyl acrylate
复制标题
丙烯酸正丁酯自由基微乳液聚合（微乳液 NMP）中有限空间效应的实验证据和有益应用
DOI：
10.1021/ma3011763
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发表时间：
2012
期刊：
影响因子：
5.5
通讯作者：
Masayoshi Okubo
中科院分区：
文献类型：
--
作者：
Yukiya Kitayama;Seita Tomoeda;Masayoshi Okubo
研究了在丙烯酸正丁酯（BA）微乳液体系（微乳液NMP）中氮氧自由基聚合（NMP）的受限空间效应，其中胶束（单体液滴）直径为5-10 nm，聚合完成时聚（BA）（PBA）粒子直径为~ 60 nm。为了阐明微乳液NMP初始阶段单体液滴直径（dm）的重要性，进行了细乳液体系中的NMP（细乳液NMP）（dm：~ 60 nm）作为比较实验。细乳液NMP在没有分子量分布（MWD）控制的情况下进行;另一方面，在微乳液NMP中，随着转化率的增加，MWD向更高的分子量转移。通过扩链实验测得细乳液和微乳液纳米粒子初始阶段的PBAs活性分别为0.01%和64%。从这些结果，可以得出结论，在微乳液NMP的初始阶段的有限空间效应有效地操作，并导致PBA与预定的分子量和良好的控制的MWD，即使聚合颗粒的直径随着转化率增加。
The confined space effect, which was found by the authors, in nitroxide-mediated radical polymerization (NMP) in a microemulsion system (microemulsion NMP) ofn-butyl acrylate (BA) was investigated, where the diameter of micelles (monomer droplets) was 5–10 nm and that of poly(BA) (PBA) particles at the completion of the polymerization was ∼60 nm. To clarify the importance of diameter of monomer droplets (dm) in the initial stage of the microemulsion NMP, NMP in a miniemulsion system (miniemulsion NMP) (dm: ∼60 nm) was carried out as a comparative experiment. The miniemulsion NMP proceeded without molecular weight distribution (MWD) control; on the other hand, in the microemulsion NMP the MWD shifted to higher molecular weight with increasing conversion. The livingnesses of PBAs obtained in the initial stages of the miniemulsion and microemulsion NMPs, which were determined by chain extension test, were 0.01% and 64%, respectively. From these results, it is concluded that the confined space effect in the initial stage of the microemulsion NMP effectively operated and resulted in PBA with predetermined molecular weight and good control of MWD even if the diameter of polymerizing particles increased with conversion.