CAREER: Design Principles for Controlled Cyclic Polymer Synthesis

职业：受控环状聚合物合成的设计原理

• 批准号: 2142922
• 负责人: Matthew Golder
• 金额: $ 70万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-02-01 至 2027-01-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2142922&HistoricalAwards=false
• 关键词: CAREER; Design; Principles; Controlled; Cyclic

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2).With the support of the Macromolecular, Supramolecular and Nanochemistry program in the Division of Chemistry, Professor Matthew R. Golder of the University of Washington is developing new synthetic approaches for the preparation of cyclic polymers. Compared to other polymer classes, cyclic polymers are unique because they lack chain ends. Cyclic polymers are currently being explored as potential candidates for next generation of drug-delivery agents, conductive materials, and thermoplastic resins. The synthesis of cyclic polymers in high purity and large quantities remains a challenge in polymer chemistry because current methodologies typically yield mixtures of linear and cyclic macromolecules which are difficult to separate. In this research, metal initiators based on ruthenium will be developed and used to control the synthesis of cyclic polymers. Detailed kinetic and mechanistic studies will be conducted to correlate the initiator structure with its reactivity in polymerization reactions. Ultimately, the developed initiators will be able to regulate reaction kinetics and molecular weight or size of cyclic polymers. If successful, this work will enable the preparation of cyclic polymeric materials with architectures that are otherwise very challenging to achieve. The research activities associated with this award will increase broadening participation and enable training of high school, undergraduate, and graduate students in synthetic polymer chemistry. The outreach program “Husky at Home Science” will reach and engage homeschooled students across the state of Washington. This activity will develop a virtual hands-on program and a children’s storybook centered around polymer science. This project will focus on the development of ruthenium-mediated ring expansion metathesis polymerization for the controlled synthesis of cyclic polymers. In the first goal, tethered ruthenium benzylidene initiators will be prepared and used to study polymerization reaction kinetics. Computational modeling will be utilized to complement the experimental synthetic and mechanistic studies. Emphasis will be placed on determining the role of initiator structure on the overall reaction profile. In the second goal, systematic studies will be conducted to gain control over the ring-closing (i.e., back-biting) of the cyclic ruthenium species relative to insertion. Decoupling monomer insertion from ring-closure could enable living polymerization in which the molecular weights of cyclic polymers will be predetermined by the ratio of monomer to the initiator. Lastly, a methodology will be developed for more accurate determination of acyclic impurities amongst cyclic polymers in ring expansion metathesis polymerization. The new technique will involve incorporation of bulky silyl ether monomers that act as single-addition degradable junctions, allowing for the union and separation of two polymer blocks. If successful, this research will advance fundamental understanding of how to control back-biting reactions in metal-mediated ring expansion metathesis polymerization, enabling the synthesis of cyclic polymers that are otherwise difficult to prepare using existing methodologies.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.

该奖项是根据2021年美国救援计划法案（公法117-2）的全部或部分资助。在化学系大分子，超分子和纳米化学计划的支持下，教授马修R。华盛顿大学的戈尔德正在开发制备环状聚合物的新合成方法。 与其他聚合物类别相比，环状聚合物是独特的，因为它们没有链端。 环状聚合物目前正被探索作为下一代药物递送剂、导电材料和热塑性树脂的潜在候选物。 高纯度和大量环状聚合物的合成仍然是聚合物化学中的挑战，因为目前的方法通常产生难以分离的线性和环状大分子的混合物。在本研究中，将开发基于钌的金属引发剂并用于控制环状聚合物的合成。 将进行详细的动力学和机理研究，以将引发剂结构与其在聚合反应中的反应性相关联。最终，开发的引发剂将能够调节反应动力学和环状聚合物的分子量或尺寸。如果成功的话，这项工作将使环状聚合物材料的制备与架构，否则是非常具有挑战性的实现。与该奖项相关的研究活动将增加参与，并使高中，本科和研究生在合成聚合物化学的培训。外展计划“哈士奇在家庭科学”将达到和从事家庭教育的学生在整个华盛顿州。这项活动将开发一个虚拟的动手程序和一本以聚合物科学为中心的儿童故事书。 本计画将著重于发展氯离子介导的扩环复分解聚合，以控制环状聚合物的合成。在第一个目标中，将制备栓系钌亚苄基引发剂并用于研究聚合反应动力学。计算建模将被用来补充实验合成和机理研究。重点将放在确定引发剂结构对整个反应曲线的作用上。在第二个目标中，将进行系统的研究，以控制闭环（即，回咬）的环状钌物质相对于插入。从闭环解耦单体插入可以实现活性聚合，其中环状聚合物的分子量将由单体与引发剂的比率预先确定。最后，将开发一种方法，用于更准确地测定在扩环复分解聚合中的环状聚合物中的非环状杂质。这项新技术将涉及掺入庞大的甲硅烷基醚单体，这些单体充当单加成可降解接头，允许两个聚合物嵌段的结合和分离。如果成功，这项研究将推进对如何控制金属介导的扩环复分解聚合反应中的反咬反应的基本理解，从而能够合成使用现有方法难以制备的环状聚合物。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估来支持。