...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Coordination chemistry reviews >Metallocene catalyzed ethene- and propene conorbornene polymerization: Mechanisms from a detailed microstructural analysis
【24h】

Metallocene catalyzed ethene- and propene conorbornene polymerization: Mechanisms from a detailed microstructural analysis

机译：茂金属催化的乙烯和丙烯共聚降冰片烯聚合：详细微观结构分析的机理

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Cyclic olefin copolymers are one of the new families of olefinic copolymers made available by metallocenes. Owing to their unique combination of properties, they are engineered polymers which are produced and commercialized. This review provides an overview of recent progress regarding ethene (E)- and propene (P)-norbornene (N) copolymerization with early transition metal catalysts. Metallocenes and some of post metallocene catalyst precursors most frequently utilized for the synthesis of norbornene copolymers are presented. The synthesis and the experimental studies which provided our current knowledge of factors governing copolymerization activity, copolymer tacticity, and molar mass are reviewed. In particular, we focus on the elucidation of E-N and P-N copolymer microstructure through ~(13)C NMR analysis. Advances in signal assignments of the complex spectra of these copolymers are reviewed together with various methodologies utilized to achieve them. The microstructural description of the E-N chain, attained from such assignments, is summarized along with information achieved on the copolymerization mechanisms. The detailed information on the microstructure of these copolymers at tetrad or at pentad level has been applied to determine the kinetic copolymerization parameters and shed light on the polymerization mechanisms. Finally, a few relevant topics which contribute to our understanding of the mechanisms of initiation, propagation, termination, and chain-transfer steps are presented. These include a few examples of modern density functional calculations, chain end groups analysis, and synthesis of hydro-oligomers.
机译：环烯烃共聚物是茂金属提供的新的烯烃共聚物家族之一。由于其独特的性能组合，它们是工程化的聚合物，可以生产并商业化。这篇综述概述了乙烯与早期过渡金属催化剂共聚合乙烯（E）和丙烯（P）-降冰片烯（N）的最新进展。介绍了茂金属和一些最常用于降冰片烯共聚物合成的后茂金属催化剂前体。综述了合成和实验研究，这些研究和实验研究提供了我们目前对控制共聚活性，共聚物立构规整度和摩尔质量的因素的了解。特别是，我们专注于通过〜（13）C NMR分析阐明E-N和P-N共聚物的微观结构。回顾了这些共聚物的复杂光谱的信号分配进展以及用于实现它们的各种方法。从这样的分配获得的E-N链的微观结构描述，以及与共聚机理有关的信息，都进行了总结。这些共聚物在四级或五级水平上的微观结构的详细信息已用于确定动力学共聚参数并阐明了聚合机理。最后，介绍了一些相关的主题，有助于我们理解启动，传播，终止和链转移步骤的机制。这些包括现代密度泛函计算，链端基分析和加氢低聚物合成的一些例子。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号