Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba, Japan.
J Phys Condens Matter. 2011 Jul 20;23(28):284108. doi: 10.1088/0953-8984/23/28/284108. Epub 2011 Jun 27.
Polyrotaxane (PR), a typical example of topological supramolecular architecture, consists of multiple cyclic molecules threaded onto a linear polymer backbone and capped with bulky end-groups. The PR system of polyethylene glycol and α-cyclodextrin (α-CD) has been extensively studied for its facile synthesis, unique molecular structure, and possible applications for various smart materials. We have previously demonstrated the fabrication of PR-based fibers without chemical cross-links by wet spinning of PR solution. In this paper, we investigate the crystal structure of α-CDs in PR fibers and the effect of drawing on it. The α-CDs in PR fiber are found to form hexagonal channel-type structure. The drawing process promotes formation of the packing arrangement of α-CDs in the c-axis because of the sliding of α-CD molecules along the polymer backbone. In addition, we demonstrate the preparation of an elastomeric PR film having similar network structure to the fibers and ethylene glycol oligomer as plasticizer.
聚轮烷（PR）是拓扑超分子结构的典型例子，由多个环状分子穿在线性聚合物主链上，并带有大体积的端基。聚乙二醇和α-环糊精（α-CD）的 PR 体系因其易于合成、独特的分子结构以及在各种智能材料中的潜在应用而得到广泛研究。我们之前已经通过 PR 溶液的湿法纺丝展示了无化学交联的 PR 基纤维的制造。在本文中，我们研究了 PR 纤维中 α-CDs 的晶体结构以及拉伸对其的影响。研究发现，PR 纤维中的 α-CDs 形成了六方通道型结构。由于α-CD 分子沿聚合物主链滑动，拉伸过程促进了 α-CDs 在 c 轴上的堆积排列的形成。此外，我们还展示了弹性 PR 薄膜的制备，该薄膜具有与纤维相似的网络结构，并且使用乙二醇低聚物作为增塑剂。
