Thermodynamics and Structure of Poly[n]catenane Melts,Macromolecules

当前位置： X-MOL 学术 › Macromolecules › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Thermodynamics and Structure of Poly[n]catenane Melts
Macromolecules ( IF 5.1 ) Pub Date : 2020-03-27 , DOI: 10.1021/acs.macromol.9b02706
Phillip M. Rauscher ₁ , Kenneth S. Schweizer _{2,

3,

4,

5} , Stuart J. Rowan _{1,

6,

7,

8} , Juan J. de Pablo _{1,

8,

9}

Affiliation

Pritzker School of Molecular Engineering, University of Chicago, 5747 South Ellis Avenue, Chicago, Illinois 60637, United States
Department of Materials Science, University of Illinois, 1304 West Green Street, Urbana, Illinois 61801-3028, United States
Materials Research Laboratory, University of Illinois, 1304 West Green Street, Urbana, Illinois 61801-3028, United States
Department of Chemical and Biomolecular Engineering, University of Illinois, 1304 West Green Street, Urbana, Illinois 61801-3028, United States
Department of Chemistry, University of Illinois, 1304 West Green Street, Urbana, Illinois 61801-3028, United States
Department of Chemistry, University of Chicago, 5747 South Ellis Avenue, Chicago, Illinois 60637, United States
Chemical and Engineering Sciences, Argonne National Laboratory, 9700 Cass Avenue, Lemont, Illinois 60439, United States
Center for Molecular Engineering, Argonne National Laboratory, 9700 Cass Avenue, Lemont, Illinois 60439, United States
Materials Science Division, Argonne National Laboratory, 9700 Cass Avenue, Lemont, Illinois 60439, United States

Motivated by recent achievements in the synthesis of interlocking polymers, the structural features of poly[n]catenanes, polymers composed entirely of interlocking rings (or macrocycles), are studied by extensive molecular dynamics simulations in the melt state. The degree of polymerization (number of links) is varied from n = 1–25 and the number of beads per macrocycle is varied from m = 15–50; the results are compared to linear chains of degrees of polymerization N = 15–175. The mechanical bonds in the system cause significant topological contributions to the pressure and potential energy density not seen in other polymer systems. The polymers themselves possess many unusual structural features at short and intermediate length scales, which can be attributed to density inhomogeneities along the polymer contour. Furthermore, the conformations of the individual macrocycles within poly[n]catenanes are quite different from those of ordinary ring polymers and depend on the topology of the macrocycle, that is, whether it is threaded by one ring (chain end) or two (chain center). At larger length scales, the poly[n]catenanes are conformationally similar to ideal linear chains, but unlike traditional (covalent) polymers, they are highly globular at low degrees of polymerization and are extremely flexible relative to their size, which inhibits interchain entanglement. Implications for poly[n]catenane material properties and synthesis are discussed.

中文翻译：

聚[ n ]环丁烷熔体的热力学和结构

出于在互锁聚合物合成方面取得的最新成就的推动，通过在熔融状态下进行广泛的分子动力学模拟，研究了由完全由互锁环（或大环）组成的聚合物聚[ n ] catenanes的结构特征。聚合度（连接数）在n = 1–25之间变化，每个大环的珠粒数在m = 15–50之间变化；将结果与聚合度N的线性链进行比较= 15–175。系统中的机械键对压力和势能密度产生显着的拓扑贡献，这是其他聚合物系统所没有的。聚合物本身在中短尺度上具有许多不同寻常的结构特征，这可归因于沿聚合物轮廓线的密度不均匀性。此外，聚[ n ] catenanes内各个大环的构象与普通环聚合物的构象完全不同，并且取决于大环的拓扑结构，即它是由一个环（链端）还是两个（链端）穿过中央）。在较大的长度范围内，poly [ n] catenanes在构象上与理想的线性链相似，但与传统的（共价）聚合物不同，它们在低聚合度下呈高球形，相对于其尺寸具有极高的柔韧性，从而抑制了链间缠结。讨论了对聚[ n ]环戊烷材料性能和合成的意义。

更新日期：2020-03-27

点击分享查看原文

点击收藏

阅读更多本刊最新论文本刊介绍/投稿指南11