Synthesis of functionalized asymmetric star polymers containing conductive polyacetylene segments by living anionic polymerization
Synthesis of functionalized asymmetric star polymers containing conductive polyacetylene segments by living anionic polymerization
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DOI：
10.1021/ja054821l
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发表时间：
2005-10-19
影响因子：
15
通讯作者：
Hirao, A
中科院分区：
文献类型：
--
作者：
Zhao, YL;Higashihara, T;Hirao, A
采用活性阴离子聚合法，以聚乙炔（PPE）为导电前驱体，聚对甲苯乙烯基亚砜（PMePVSO）为导电单体，合成了聚苯乙烯、聚α-甲基苯乙烯、聚4-甲氧基苯乙烯、聚4-三甲基硅基苯乙烯和聚4-甲基苯乙烯等3-臂ABC、4-臂ABCD和5-臂ABCDE不对称星星聚合物.该方法涉及DPE官能化的聚合物与活性阴离子聚合物的加成反应，然后由原位形成的聚合物阴离子与两个、三个或四个聚合物链段引发MePVSO的活性阴离子聚合。通过SEC、1H NMR、SLS和元素分析证实，所得不对称星星聚合物具有预定的分子量、窄的分子量分布（Mw/Mn< 1.03）和所需的组成。热重分析和元素分析表明，在热处理后，星星聚合物中的PMePVSO链段可以完全转化为导电的聚乙炔链段。这些不对称的星星聚合物有望表现出有趣的溶液性质和独特的微相分离的形态超结构，在纳米导电材料中具有潜在的应用。此外，该方法可以提供具有在宽范围内变化的臂段的目标不对称星星聚合物，并且能够合成更复杂的大分子结构。
Novel 3-arm ABC, 4-arm ABCD, and 5-arm ABCDE asymmetric star polymers comprising the conductive polyacetylene precursor, poly(4-methylphenyl vinyl sulfoxide) (PMePVSO), and other segments, such as polystyrene, poly(α-methylstyrene), poly(4-methoxystyrene), poly(4-trimethylsilylstyrene), and poly(4-methylstyrene), were synthesized by the methodology based on living anionic polymerization using DPE-functionalized polymers. This methodology involves the addition reaction of a DPE-functionalized polymer to a living anionic polymer followed by the living anionic polymerization of MePVSO initiated from the in situ formed polymer anion with two, three, or four polymer segments. The resultant asymmetric star polymers possessed predetermined molecular weights, narrow molecular weight distributions (Mw/Mn< 1.03), and desired compositions as confirmed by SEC,1H NMR, SLS, and elemental analysis. After thermal treatment, the PMePVSO segment in the star polymer could be completely converted into a conductive polyacetylene segment, evident from TGA and elemental analysis. These asymmetric star polymers are expected to exhibit interesting solution properties and unique microphase-separated morphological suprastructures with potential applications in nanoscopic conductive materials. Moreover, this methodology can afford the target asymmetric star polymers with arm segments varying in a wide range and enables the synthesis of more complex macromolecular architectures.