Revolutionary and Efficient Synthesis of Cyclic Polymers

化学系的大分子、超分子和纳米化学项目正在支持佛罗里达大学的Adam Veige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差异。塑料通常由被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，在一定程度上要为工业化国家目前享有的高标准和高质量的生活负责。聚合物有许多不同的拓扑结构（形状），但最常见的是长线性链。获取这种新型聚合物并确定其独特的性能可能为功能材料的开发创造新的机会。通过参与这个跨学科项目，研究生和本科生获得了现代无机和聚合物合成和表征的各种先进技术技能。聚合物的性质部分是由它们的链端决定的。环状聚合物本身没有链端，因此产生了独特的物理性质。即使在几十年后，研究环状聚合物仍然是一个挑战。因此，聚合物化学长期以来面临的挑战是如何从现成的单体中高效地合成具有多种成分、高纯度、高分子量的环状聚合物。该提案通过采用佛罗里达大学开发的新催化剂技术来解决合成纯环状聚合物的挑战。该项目涉及合成具有高分子量的大环多烯的第一个例子。特别令人感兴趣的是合成了第一个环聚丙烯的例子并检验了它的弹性。另一个重要的目标是环聚乙炔。母体线性聚乙炔，当掺杂时，仍然是已知的导电性能最高的聚合物之一，尽管由于它在空气中不稳定且难以处理，它的用途有限。这是该项目的目的之一，以研究如何导电性能，溶解度，稳定性不同的环状版本。易于获得众所周知的线性聚合物的环状类似物为研究基本的结构-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.