Efficient Synthesis of Narrowly Dispersed Brush Polymers via Living Ring-Opening Metathesis Polymerization of Macromonomers
Efficient Synthesis of Narrowly Dispersed Brush Polymers via Living Ring-Opening Metathesis Polymerization of Macromonomers
复制标题
DOI：
10.1021/ma900280c
复制
发表时间：
2009-06-09
期刊：
影响因子：
5.5
通讯作者：
Grubbs, Robert H.
中科院分区：
文献类型：
--
作者：
Xia, Yan;Kornfield, Julia A.;Grubbs, Robert H.
通过铜催化的降冰片烯部分与采用原子转移自由基聚合制备的聚丙烯酸甲酯、聚丙烯酸叔丁酯和聚苯乙烯的链端的“点击”偶联，有效合成了各种大分子单体（MM）。使用高活性、快速引发的钌催化剂(H(2)IMes)(pyr)(2)(Cl)(2)RuCHPh在室温下在THF中进行这些MM的开环复分解聚合(ROMP)。研究发现，MM 的 ROMP 与 MM 的几乎定量转化率 (> 90%) 存在关系，产生的刷状聚合物具有 1.01-1.07 的极低多分散指数和 200-2600 kDa 的高 Mn。此类 MM 的高效 ROMP 可以方便地获得各种刷状聚合物，并克服了以前在 MM 受控聚合方面的困难。刷状聚合物产品的原子力显微镜显示，由于密集接枝侧链的显着空间排斥，导致了延伸的蠕虫状形状。
Various macromonomers (MMs) were efficiently synthesized through the copper-catalyzed "click" coupling of a norbornene moiety to the chain end of poly(methylacrylate), poly (t-butylacrylate), and polystyrene that were prepared using atom transfer radical polymerization. Ring-opening metathesis polymerization (ROMP) of these MMs was carried out using the highly active, fast-initiating ruthenium catalyst (H(2)IMes)(pyr)(2)(Cl)(2)RuCHPh in THF at room temperature. ROMP of MMs was found to be living with almost quantitative conversions (>90%) of MMs, producing brush polymers with very low polydispersity indices of 1.01-1.07 and high M-n's of 200-2600 kDa. The efficient ROMP of such MMs provides facile access to a variety of brush polymers and overcomes previous difficulties in the controlled polymerization of MMs. Atomic force microscopy of the brush polymer products revealed extended, wormlike shapes as a result of significant steric repulsion of densely grafted side chains.