Polymer Journal ( IF 2.3 ) Pub Date : 2023-12-19 , DOI: 10.1038/s41428-023-00852-y Yuki Nakama , Satoshi Natori , Shigetaka Hayano , Takahiro Sato
The characteristic ratios C∞ of syndiotactic, isotactic, and atactic hydrogenated ring-opened poly(norbornene)s, H-poly(NB)s, were determined in 1,2,4-trichlorobenzene (TCB) at 140 °C with molecular dynamics simulations and size exclusion chromatography with a multiangle light-scattering online detector (SEC-MALS). The C∞ results were 11, 14 and 12 for syndiotactic, isotactic and atactic H-poly(NB), respectively, all of which were consistent with the rotational isomeric state model. These C∞ values for H-poly(NB)s were definitely larger than those for polyethylene and syndiotactic and isotactic polypropylenes. The stiffness of the H-poly(NB) chains was induced by the internal rotations of two main-chain bonds included in the cyclopentane ring in each H-poly(NB) repeat unit, which were restricted near the trans conformation.
中文翻译:
氢化开环聚降冰片烯在稀溶液中的构象
间规、等规、无规氢化开环聚的特征比C∞降冰片烯)、H-聚(NB),在 1,2,4-三氯苯 (TCB) 中于 140°C 下通过分子动力学模拟和使用多角度光散射在线检测器 (SEC-MALS) 的尺寸排阻色谱法进行测定。间规、等规和无规 H-poly(NB) 的 C∞ 结果分别为 11、14 和 12,分别与旋转异构态模型一致。 H-poly(NB) 的这些 C∞ 值绝对大于聚乙烯、间同立构和全同立构的值聚丙烯。 H-poly(NB)链的刚度是由每个H-poly(NB)重复单元中环戊烷环中包含的两个主链键的内旋转引起的,这些主链键被限制在构象。