...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Macromolecular symposia >NMR Observation of the Conformations and Motions of Polymers Confined to the Narrow Channels of Their Inclusion Compounds
【24h】

NMR Observation of the Conformations and Motions of Polymers Confined to the Narrow Channels of Their Inclusion Compounds

机译：核磁共振观察的聚合物的包容化合物的狭窄通道的构象和运动

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

When polymers are guests in crystalline inclusion compounds (ICs) formed with small-molecule hosts, they occupy a unique environment. In a cocrystallization process the small-molecule host forms a crystalline lattice containing long narrow channels where the guest polymer chains are included. Because of the narrow channel diameter and because neighboring channels are separated by walls formed exclusively from the small-molecule host lattice, the included polymer chains are highly extended and separated from polymer chains in other IC channels. As a consequence, polymer-IC crystals provide a unique solid state environment for the included polymer chains and serve as models useful for assessing the contributions made by the inherent behavior of individual polymer chains to the properties of ordered, bulk polymers, which can be obscured by pervasive interactions between their tightly packed polymer chains. In this paper we describe the conformations and motions of polymer chains confined to the narrow channels of the following polymer-ICs: i. polyethylene and trans-1, 4-polybutadiene in their ICs with perhydrotriphenylene, ii. polyepsilon caprolactone and its diblock and triblock copolymers with polybutadiene and poly (ethylene oxide)in their ICs with urea, and iii. nylon-6 in its ICs with alpha-, beta-, and gamma-cyclodextrins. High resolution, solid state NMR serves as both the conformational (C-13 chemical shifts) and motional (relaxation times and line shapes) probe. Comparison with identical NMR measurements performed on the bulk homo- and copolymer samples permits us to draw several conclusions regarding the relationships between the conformations and motions of polymers and their dependence on their ordered solid state environments.
机译：当聚合物成为与小分子主体形成的结晶夹杂物（IC）的客体时，它们会占据独特的环境。在共结晶过程中，小分子主体形成包含长而窄的通道的晶格，其中包含客体聚合物链。由于狭窄的通道直径，并且由于相邻的通道被仅由小分子主体晶格形成的壁隔开，因此所包含的聚合物链高度延伸，并与其他IC通道中的聚合物链分离。结果，聚合物-IC晶体为包含的聚合物链提供了独特的固态环境，并用作模型，可用于评估单个聚合物链的固有行为对有序的块状聚合物的性能所做出的贡献，这些属性可能会被掩盖它们紧密堆积的聚合物链之间的普遍相互作用。在本文中，我们描述了局限于以下聚合物-IC狭窄通道的聚合物链的构象和运动：聚乙烯和反式1,4-聚丁二烯与全氢联苯的ICs; ii。聚ε-己内酯及其二嵌段和三嵌段共聚物与聚丁二烯和聚环氧乙烷在其含尿素的IC中的作用; iii。 IC中含有尼龙6，β和γ环糊精。高分辨率固态NMR既可以用作构象（C-13化学位移）又可以用作运动（弛豫时间和线形）探针。与对本体均聚物和共聚物样品进行的相同NMR测量的比较，使我们可以得出关于聚合物的构象与运动之间的关系以及它们对有序固态环境的依赖性的几个结论。

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