Polymers of Unusual Topology using Heterogeneous ROMP Catalysts

使用异质 ROMP 催化剂的异常拓扑聚合物

基本信息

批准号：
1807154
负责人：
Robert Grubbs
金额：
$ 64万
依托单位：
California Institute of Technology
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2018
资助国家：
美国
起止时间：
2018-08-01 至 2022-01-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1807154&HistoricalAwards=false
关键词：
Polymers Unusual Topology using Heterogeneous

项目摘要

Polymers are ubiquitous in our everyday lives. They are plastics, rubbers or gels, and in living systems they serve a structural role as proteins, and also the source of genetic information as DNA and RNA. Small chemical units (monomers) are linked together to produce a polymer with any number of desired functions. The characteristics of the polymer are determined both by the monomer, and how the monomer units are connected. Professor Grubbs at the California Institute of Technology in Pasadena, CA develops new methods for producing polymers, specifically on developing new types of polymers with complex structures which generate new materials for important commercial and academic uses. One important approach involves very long polymer chains where the ends are connected, so that the resulting cyclic polymer does not have a beginning or end. These polymers are challenging to produce. Many theories suggest cyclic polymers will have different properties than identical polymers where the ends are not connected. Polymers with enhanced properties are anticipated to result from this work. This project provides an excellent platform for research training of scientists and helps to prepare a skilled workforce for academia and industry.Ring-opening metathesis polymerization (ROMP) is a critical tool in polymer synthesis and is used to produce numerous model systems, as well as a number of commercial materials. Most of the work to date in Professor Grubbs' group utilizes homogeneous catalysts that are easy to control and are manipulated to produce well-defined polymeric structures. Although less common, heterogeneous catalysts are also used to provide new materials. In one case, the catalyst is covalently linked to a silica support in such a way that cyclic polymers are selectively produced. The heterogeneous system maintains the cyclic structure of the polymer throughout the reaction, and releases the cyclic polymer from the support, which provides a simple way to separate the product from the catalyst. The resulting high molecular weight hydrocarbon polymers provide model materials for verification of a variety of theoretical predictions. Additionally, large-scale synthesis of such material enables previously unrealized commercial applications. Another novel strategy uses a monomer which is introduced in the gas-phase to a heterogeneous system, which produces polymers with different properties than those formed in solution. This method provides hydrocarbon polymers which are not accessible using homogeneous catalysts.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

聚合物在我们的日常生活中无处不在。它们是塑料，橡胶或凝胶，在生物系统中，它们是蛋白质的结构作用，也是作为DNA和RNA的遗传信息来源。将小型化学单元（单体）连接在一起，以产生具有许多所需功能的聚合物。聚合物的特性既由单体决定，又是如何连接单体单位的。加利福尼亚州帕萨迪纳市加利福尼亚理工学院的Grubbs教授开发了生产聚合物的新方法，特别是开发具有复杂结构的新型聚合物，这些结构为重要的商业和学术用途生成了新材料。一种重要的方法涉及连接末端的非常长的聚合物链，因此所得的循环聚合物没有开始或末端。这些聚合物的生产具有挑战性。许多理论表明，环状聚合物的性质将具有不同的特性，而末端未连接的相同聚合物。这项工作预计将产生具有增强性能的聚合物。该项目为科学家的研究培训提供了一个绝佳的平台，并有助于为学术界和行业准备熟练的劳动力。开启的元理解聚合（ROMP）是聚合物合成的关键工具，可用于生产众多模型系统以及许多商业材料。迄今为止，Grubbs教授组的大多数工作都利用易于控制并操纵以产生定义明确的聚合结构的均匀催化剂。尽管不常见，但异质催化剂也用于提供新材料。在一种情况下，将催化剂共价与二氧化硅载体相关，以选择性地产生环状聚合物。在整个反应过程中，异质系统保持聚合物的循环结构，并释放出循环聚合物从支撑物中释放出来，这提供了一种简单的方法，可以将产物与催化剂分离。所得的高分子量烃聚合物提供了模型材料，以验证各种理论预测。此外，这种材料的大规模合成可实现以前未实现的商业应用。另一种新型策略使用单体，该单体在气相中引入到异质系统中，该系统产生的聚合物与溶液中形成的聚合物不同。该方法提供了使用均质催化剂无法访问的碳氢化合物聚合物。该奖项反映了NSF的法定任务，并且使用基金会的知识分子优点和更广泛的影响审查标准，被认为值得通过评估来获得支持。