Solid-State Dynamics, Phase Structure, and Properties of Rotaxanated Polymers

旋转化聚合物将用各种分析技术进行检查，以建立这类材料的结构/迁移率/性能关系。两种类型的聚轮烷描述基于非常不同的大环组分：(1)冠醚，(2)环糊精。在以冠醚为基础的旋烷化聚合物中，大环通常比主骨架更具流动性。在基于环糊精的旋转烷化聚合物中，大环形成刚性的氢键隧道，其中线性聚合物骨干比没有螺纹时表现出更大的流动性。这些动态结构对体物理性质的影响将被探索和比较。特别是，冲击强度和微相分离将研究一系列冠醚基旋烷化聚合物作为大循环载荷的函数。通过环糊精对线性聚合物的轮烷化反应，我们将制备并评价两种新的结构：(1)轮烷化和非轮烷化链段的铰接结构，以及(2)螺纹交联。通过固态核磁共振、x射线散射和电子显微镜获得的固态动力学和相结构信息将与热学和力学性能相关联。本研究方向为新型高分子材料和有机材料的表征。

Rotaxantated polymers will be examined with a variety of analytical techniques to establish structure/mobility/property relationships for this class of materials. Two types of polyrotaxanes are described based on very different macrocyclic components: (1) crown ethers, and (2) cyclodextrins. In crown-ether-based rotaxanated polymers, the macrocycle is typically more mobile than the host backbone. In cyclodextrin-based rotaxanated polymers, the macrocycles form rigid hydrogen-bonded tunnels inside which the linear polymer backbones can exhibit greater mobility than when not threaded. The consequences of these dynamic architectures on bulk physical properties will be explored and compared. In particular, impact strength and microphase separation will be investigated for a series of crown-ether-based rotaxanated polymers as a function of macrocycle loading. Two novel constructions will be prepared and evaluated from the rotaxanation of linear polymers with cyclodextrins: (1) articulated structures of rotaxanated and nonrotaxanated chain segments, and (2) threaded crosslinking. Thermal and mechanical properties will be correlated with information on solid-state dynamics and phase structures obtained through solid-state NMR, x-ray scattering, and electron microscopy.This research is in the area of characterization of novel polymeric and organic materials.