CAREER: Novel Approaches to Hyperbranched Polymers

职业：超支化聚合物的新方法

• 批准号: 2237487
• 负责人: Michael Schulz
• 金额: $ 72.5万
• 依托单位: Virginia Polytechnic Institute and State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-05-15 至 2028-04-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2237487&HistoricalAwards=false
• 关键词: CAREER; Novel; Approaches; Hyperbranched; Polymers

With the support of the Macromolecular, Supramolecular and Nanochemistry program in the Division of Chemistry, Michael D. Schulz of Virginia Polytechnic Institute and State University is developing self-condensing ring opening metathesis polymerization (ROMP) to prepare hyperbranched polymers. Highly and hyperbranched polymers are tree-like 3D macromolecules that have very different viscosity characteristics when compared to linear polymers. As a result, hyperbranched polymers have been applied in various applications ranging from their use as additives to coatings and as sensors, as high loading supports in combinatorial chemistry, and as homogeneous catalysts. In this research, inimers—small molecules that can act as both an initiator and a monomer—will first be synthesized. Structural modifications will also be conducted to optimize polymerization activity. Successfully prepared inimers will then be used in self-condensing polymerization to prepare several hyperbranched polymers with interesting structural and mechanical properties. This research has the potential to lay the foundation for the synthesis of new class of plastics with controlled macromolecular structures. The project will also serve as an excellent vehicle for training students in polymer chemistry and catalysis. A chemistry-themed educational outreach with demonstrations at the Science Museum of West Virginia will focus on polymers in the modern world and how their properties are dependent on chemical structure. A travelling kit will also be developed for visits to rural communities that are under-resourced in science education. The project will focus on controlled synthesis of hyperbranched polymers using ruthenium-catalyzed self-condensing ring opening metathesis polymerization (ROMP). The central approach will involve the preparation of latent-initiating olefin metathesis catalysts with modified benzylidene ligands that will be coupled to a ROMP monomer, producing an olefin metathesis inimer. The synthesized inimers will be systematically investigated to examine the effects of structural modification on latency control, activation, and polymerization properties. Successful candidates will then be used to prepare hyperbranched polymers. A strong focus will be on investigating the interplay among polymerization conditions, polymerization kinetics, hyperbranched structures, and strategies for end-group modification. Lastly, structure-property relationships in the synthesized polymers will be systematically investigated. This project has the potential to produce a powerful strategy to synthesize hyperbranched ROMP polymers with controlled branching, repeat-unit functionality, and end-groups.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.

在化学部的大分子，超分子和纳米化学计划的支持下，弗吉尼亚理工学院和州立大学的迈克尔·D·舒尔茨（Michael D.与线性聚合物相比，高度和超支的聚合物是树状的3D大分子，具有粘度非常不同的特性。结果，超支聚合物已用于各种应用中，从用作添加剂到涂料和传感器，作为组合化学中的高负载支持，以及均质催化剂。在这项研究中，首先合成了既可以充当引发剂又可以充当单体的小分子。还将进行结构修饰以优化聚合活性。然后，成功制备的捕获物将用于自键合聚合物，以制备具有有趣的结构和机械性能的多个超支聚合物。这项研究有可能为与受控的大分子结构合成新类塑料的基础。该项目还将成为培训聚合物化学和催化学生的绝佳工具。在西弗吉尼亚州科学博物馆举行的化学主题教育宣传活动将重点关注现代世界中的聚合物，以及它们的特性如何依赖化学结构。旅行套件还将开发用于参观科学教育中资源不足的农村社区。该项目将使用芳族催化的自调节环开放式分解聚合聚合物（ROMP）来关注超支聚合物的控制合成。中心方法将涉及用改良的苯二烯配体制备潜在的烯烃分解催化剂，这些苯甲酸配体将偶联与romp单体偶联，从而产生烯烃的分解含量。合成的捕集剂将进行系统研究，以检查结构修饰对潜伏期控制，激活和聚合特性的影响。然后，成功的候选人将用于制备超支聚合物。重点是研究聚合条件，聚合动力学，超支结构以及最终组修饰的策略之间的相互作用。最后，将系统地研究合成聚合物中的结构 - 特性关系。该项目有可能制定有强大的策略，以通过受控的分支，重复单位功能和终点组合超支的ROMP聚合物综合。该奖项反映了NSF的法定任务，并被认为是通过基金会的知识分子优点和更广泛的影响标准来评估来获得的支持。