Revolutionary and Efficient Synthesis of Cyclic Polymers

化学系的大分子、超分子和纳米化学计划正在支持佛罗里达大学的Adam Veige教授和Brent Sumerlin教授合成和表征环状聚合物，并确定这些聚合物与其线性类似物之间的区别。塑料通常由称为聚合物的长链状分子组成。塑料在现代生活中无处不在，部分原因是工业化国家目前享有的高标准和高质量的生活。聚合物有许多不同的拓扑(形状)，但最常见的是长线性链。访问这类新的聚合物并确定其独特的性能可能会为功能材料的开发创造新的机会。通过参与这个跨学科的项目，研究生和本科生获得了现代无机和聚合物合成以及表征方面的各种高级技术技能。聚合物的性质在一定程度上由其链端决定。环状聚合物天生没有链端，因此产生了独特的物理性能。即使在几十年后，环状聚合物的研究仍然是一个挑战。因此，从易得的单体出发，有效地合成组成多样、高纯度、高相对分子质量的环状聚合物是聚合物化学中的一个长期挑战。这项建议解决了通过使用佛罗里达大学开发的新催化剂技术来合成纯环状聚合物的挑战。该项目包括合成第一批具有高分子量的大环多烯。特别令人感兴趣的是合成第一个环状聚丙烯的例子，并检验其规整性。另一个重要的目标是环状聚乙炔。当掺杂时，母体线性聚乙炔仍然是已知的最高导电聚合物之一，尽管它的用途有限，因为它在空气中不稳定，而且很难处理。本项目的目的之一是研究循环版本的导电性能、溶解度和稳定性有何不同。方便地获得众所周知的线性聚合物的环状类似物为研究基本结构-性质关系提供了一种方便的方法。

With thia award, the Macromolecular, Supramolecular and Nanochemistry Program of the Division of Chemistry is supporting Professors Adam Veige and Brent Sumerlin of the University of Florida to synthesize and characterize polymers that are cyclic and to establish the differerences between these polymers and their linear analogs.Plastics are often comprised of long chain-like molecules called polymers. Plastics are ubiquitous in modern life and in part are responsible for the current high standard and quality of life enjoyed by industrialized nations. Polymers have many different topologies (shapes), but most commonly they are long linear chains. Accessing this new class of polymers and determining their unique properties may create new opportunities for the development of functional materials. Through participating in this cross-disciplinary project, graduate and undergraduate students acquire a diverse set of advanced technical skills for modern inorganic and polymer synthesis and for characterization. The properties of polymers are, in part, dictated by their chain ends. Cyclic polymers inherently do not have chain ends, and as a consequence, unique physical properties arise. Investigating cyclic polymers remains a challenge even after many decades. Thus, a longstanding challenge in polymer chemistry is to synthesize cyclic polymers efficiently, with diverse compositions, high purity, high molecular weights, and from readily available monomers. This proposal addresses the challenge of synthesizing pure cyclic polymers by employing new catalyst technology developed at the University of Florida. The project involves the synthesis of the first examples of macrocyclic polyenes with high molecular weights. Of particular interest is the synthesis of the first example of cyclic polypropylene and to examine its tacticity. Another important target is cyclic polyacetylene. The parent linear polyacetylene, when doped, remains one of the highest conducting polymers known, though it has limited use since it is unstable in air and intractable. It is one of the aims of this project to investigate how the conductive properties, solubility, and stability differ for the cyclic version. Facilitated access to cyclic analogs of well-known linear polymers provides a convenient method to investigate fundamental structure-property relationships.