Chain extension of center-functionalized polystyrene via radical–radical coupling: Periodic introduction of complementary hydrogen bonding interaction site on polymer chain
Chain extension of center-functionalized polystyrene via radical–radical coupling: Periodic introduction of complementary hydrogen bonding interaction site on polymer chain
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通过自由基-自由基耦合进行中心官能化聚苯乙烯的扩链：在聚合物链上定期引入互补氢键相互作用位点
DOI：
10.1016/j.eurpolymj.2014.08.027
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发表时间：
2015
影响因子：
6
通讯作者：
Mitsuo Sawamoto
中科院分区：
文献类型：
--
作者：
Sang-Ho Lee;Makoto Ouchi;Mitsuo Sawamoto
在这项工作中，我们的目的是针对独特的聚苯乙烯（PSt）的合成周期性地进行互补的氢键相互作用网站的链。首先，一个双功能（双头）引发剂携带三点互补氢键位点（Cl-DAD-Cl：D =氢供体; A =氢受体）用于催化苯乙烯的活性自由基聚合。精确控制的聚合允许定量引入的DAD单元在中心和Cl封端基团在终端的所得PSt链以及窄的分子量分布。在不存在单体的情况下，从两端的C-Cl键产生集中的自由基物种诱导苯乙烯基自由基物种之间的自由基-自由基偶联反应，用于“扩链”。由于前体的分子量分布足够窄（Mw/Mn< 1.10）并且DAD单元定量地结合在中心位置，因此所得聚合物链以对应于前体的链长（分子量）的规则间隔携带互补相互作用位点。位置可控的聚苯乙烯链与中心具有互补相互作用单元（ADA）的聚甲基丙烯酸甲酯相互作用，得到超分子接枝共聚物。
In this work, our purpose was directed to syntheses of unique polystyrene (PSt) periodically carrying complementary hydrogen-bonded interaction sites in the chain. First, a bifunctional (bi-headed) initiator carrying three-point complementary hydrogen bonding sites (Cl–DAD–Cl: D = hydrogen donor; A = hydrogen acceptor) was employed for ruthenium-catalyzed living radical polymerization of styrene. Precise control of the polymerization allowed quantitative introduction of the DAD unit at the center and Cl capping group at the terminals for the resultant PSt chain as well as narrow molecular weight distribution. Generation of concentrated radical species from the C–Cl bonds at the both terminals in the absence of monomer induced radical–radical coupling reaction between the styryl radical species for “chain extension”. Since molecular weight distribution of the precursor was enough narrow (Mw/Mn< 1.10) and the DAD unit was quantitatively incorporated at the central position, the resultant polymer chains carried the complementary interaction site at regular interval corresponding to the chain length (molecular weight) of the precursor. The position-controlled polystyrene chain interacted with poly(methyl methacrylate) having the complementary interaction unit (ADA) at the center to give supramolecular graft copolymer.