Microflow System Controlled Anionic Polymerization of Alkyl Methacrylates
Microflow System Controlled Anionic Polymerization of Alkyl Methacrylates
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DOI：
10.1021/ma900551a
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发表时间：
2009-06
期刊：
影响因子：
5.5
通讯作者：
A. Nagaki;Yutaka Tomida;A. Miyazaki;J. Yoshida
中科院分区：
文献类型：
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作者：
A. Nagaki;Yutaka Tomida;A. Miyazaki;J. Yoshida
具有明确结构的聚甲基丙烯酸烷基酯的合成已引起学术界和工业界的极大兴趣。1如今，聚（甲基丙烯酸烷基酯）被用作通用材料，如塑料，粘合剂和弹性体，含有许多不同的反应功能。通常，这些市售的甲基丙烯酸酯聚合物通过自由基聚合方法制备。活性自由基聚合方法的最新发展提供了很大的希望，2并且已经开发了许多使用封端剂的方法，例如变性或交换链转移、原子转移自由基聚合、氮氧介导的自由基聚合和可逆加成断裂链转移聚合。3相反，甲基丙烯酸烷基酯的活性阴离子聚合不需要封端剂。4因此，活性阴离子聚合与活性自由基聚合相比非常快。活性阴离子聚合还提供了容易获得定制的大分子，例如接枝、嵌段、星星、R、ω双官能聚合物和大分子单体。然而，在常规的大批量反应器中，甲基丙烯酸烷基酯的活性阴离子聚合应该在低温如r78 ℃下进行，以获得窄分子量分布的聚合物。这种低温的要求严重限制了这种非常有用的聚合技术在工业上的应用。最近，微流系统中的聚合引起了人们的极大关注，10并且已经报道了对乙烯基单体的自由基11和阳离子聚合12的广泛研究。然而，据我们所知，只有少数报道使用微流系统的阴离子聚合已公布。13因此，我们启动了甲基丙烯酸烷基酯的活性阴离子聚合项目，在此我们报告了这项研究的结果。开发了具有不同抗衡离子如Li+、Na+、K+和Cs+的各种引发剂用于甲基丙烯酸甲酯（MMA）的阴离子聚合。其中李玉明的人缘很好。在大批量体系中，有机锂引发MMA的活性阴离子聚合应在低温（如78 ℃）下进行。必须使用添加剂如LiClO 4和N，N，N 0，N 0-四甲基乙二胺（TMEDA）以在较高温度如r20和r40 ℃下完成聚合。15然而，这些添加剂污染了
Synthesis of poly (alkyl methacrylate) s with well-defined structures has received significant research interests from both academic and industrial polymer chemists. 1 Nowadays, poly (alkyl methacrylate) s are utilized as versatile materials such as plastics, adhesives and elastomers containing a number of different reactive functions. In general, these commercially available methacrylate polymers are prepared by radical polymerization processes. Recent development in living radical polymerization method offers great promise, 2 and a number of methods using a capping agent have been developed such as degeneration or exchange chain transfer, atom transfer radical polymerization, nitroxide-mediated radical polymerization, and reversible additionrfragmentation chain transfer polymerization. 3 In contrast, living anionic polymerization of alkyl methacrylates does not need a capping agent. 4 Therefore, living anionic polymerization is very fast compared to living radical polymerization. Living anionic polymerization also provides easy access to tailor-made macromolecules, such as graft, block, star, R, ωdifunctional polymers and macromonomers. 5 However, in a conventional macrobatch reactor, living anionic polymerization of alkyl methacrylates should be carried out at low temperatures such as r78 C to obtain polymers of narrow molecular weight distribution. 6 The requirement of such low temperatures causes severe limitations in the use of this highly useful polymerization technology in industry.Recently, polymerization in microflow systems7r9 has attracted a great deal of attention, 10 and extensive studies on radical11 and cationic polymerization12 of vinyl monomers have been reported. However, to the best of our knowledge, only a few reports on the use of microflow systems for anionic polymerization have been published. 13 Thus, we initiated our project on living anionic polymerization of alkyl methacrylates, and herein we report the results of this study. Various initiators having different counterions such as Li þ, Na þ, K þ, and Cs þ are developed for anionic polymerization of methyl methacrylate (MMA). Among them, Li þ is very popular. In a macrobatch system, organolithium-initiated living anionic polymerization of MMA should be carried out at low temperatures such as r78 C. 14 It is necessary to use an additive such as LiClO4 and N, N, N 0, N 0-tetramethylethylenediamine (TMEDA) to accomplish the polymerization at higher temperatures such as r20 and r40 C. 15 However, these additives contaminate the