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.

在化学系大分子、超分子和纳米化学项目的支持下，迈克尔·D·美国弗吉尼亚理工学院和州立大学的Schulz正在开发自缩合开环易位聚合（ROMP）来制备超支化聚合物。高度和超支化聚合物是树状3D大分子，与线性聚合物相比具有非常不同的粘度特性。因此，超支化聚合物已被应用于各种应用中，从它们用作涂料的添加剂和传感器，作为组合化学中的高负载载体，以及作为均相催化剂。在这项研究中，将首先合成inimers-既可以作为引发剂又可以作为单体的小分子。还将进行结构修饰以优化聚合活性。成功制备的引发剂将用于自缩合聚合，制备具有有趣结构和力学性能的超支化聚合物。这项研究有可能为合成具有可控大分子结构的新型塑料奠定基础。该项目也将作为一个优秀的工具，培养学生在聚合物化学和催化。在西弗吉尼亚州科学博物馆举行的以化学为主题的教育宣传活动将侧重于现代世界的聚合物以及它们的性质如何依赖于化学结构。还将为访问科学教育资源不足的农村社区开发一套旅行工具。该项目将集中在超支化聚合物的控制合成，使用铼催化的自缩合开环易位聚合（ROMP）。中心方法将涉及制备具有改性亚苄基配体的潜在引发烯烃复分解催化剂，所述改性亚苄基配体将偶联至ROMP单体，产生烯烃复分解引发剂单体。合成的inimers将进行系统的研究，以检查潜伏期控制，激活和聚合性能的结构修饰的影响。成功的候选物将用于制备超支化聚合物。一个强有力的重点将是调查聚合条件，聚合动力学，超支化结构和端基改性策略之间的相互作用。最后，将系统地研究合成的聚合物的结构-性能关系。该项目有可能产生一个强大的战略，以合成超支化开环易位聚合物与控制支化，重复单元功能，和end-groups.This奖项反映了NSF的法定使命，并已被认为是值得通过评估使用基金会的智力价值和更广泛的影响审查标准的支持。