Elucidating Ring Opening Metathesis Copolymerization Thermodynamics of Monomers with Dissimilar Ring Strain Energies

阐明不同环应变能单体的开环复分解共聚热力学

• 批准号: 2305099
• 负责人: Justin Kennemur
• 金额: $ 45.98万
• 依托单位: Florida State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-05-01 至 2026-04-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2305099&HistoricalAwards=false
• 关键词: Elucidating; Ring; Opening; Metathesis; Copolymerization

With the support of the Macromolecular, Supramolecular and Nanochemistry program in the Division of Chemistry, Professor Justin G. Kennemur of Florida State University is studying copolymerization thermodynamics of cyclic monomers in ring opening metathesis polymerization (ROMP). Copolymerization of two or more individual monomers into one macromolecule or polymer offers a divergent means of producing societal plastics that contain distributed functionality for a myriad of applications. Specifically, ROMP affords a variety of industrially relevant polyolefin-based materials through chain growth of strained cycloolefin monomers using well-established catalysts. This Kennemur team will perform systematic synthetic, kinetic and mechanistic studies to gain understanding of how basic thermodynamic principles along with key conditions, such as catalyst and solvent, ultimately dictate the reactivity ratios of various cycloolefin comonomers and their sequencing within the macromolecular chains that are grown. The project will also introduce new biomass-based terpene cycloolefins to provide a thermodynamic spectrum of medium ring-strain not afforded by the commonly employed cycloolefin monomers in ROMP. The research team will continue engagement with the first ever American Chemical Society Division of Polymer Chemistry and Division of Polymer Materials Science and Engineering student chapter that is co-established between a historically black college/university of Florida Agricultural and Mechanical University (FAMU) and an R1 research university in Florida State University. This student chapter will bring together a highly diverse body of students and faculty aimed at polymer science research. This unique platform will additionally be utilized to promote the growth of graduate and undergraduate students towards the development of leadership, both governed by outreach and the development of a new Florida-based conference, centered on polymer science.This project will focus on elucidating ring opening metathesis copolymerization thermodynamics of monomers with dissimilar ring strain energies. In the first aim, reactivity ratios of low-strain cyclopentene monomers that are highly sensitive to slight variations in their ring strain energy (RSE) will be determined using modern integrated approaches. Determined parameters will then be correlated to monomer sequencing within the polymer microstructure as a function of thermodynamic principles (monomer concentration, stoichiometry, and temperature). The second aim will examine, delta-pinene, and its variant, apopinene , which have RSEs that are in-between the high strain and low strain monomers typically employed in ROMP. Fundamental thermodynamic investigations and copolymerizations of these terpene-based monomers with each other and with low/ high RSE monomers will also be explored. Finally, the last specific aim will push the limits of disparity between RSEs by investigating high strain and low strain monomers in combination. Such investigations have potential for both alternating and blocky sequencing strategies. Taken together, these studies have the potential to provide guiding principles for the rational design of copolymers from readily available cycloolefin monomers; there is the potential to uncover basic principles that will apply to ring-opening polymerization (ROMP), in general, and thereby have a significant long-term scientific impact on polymer chemistry.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，佛罗里达州立大学的Justin G. Kennemur教授正在研究开环复分解聚合（ROMP）中环状单体的共聚热力学。两个或多个单体共聚成一个大分子或聚合物提供了一种不同的方法来生产社会塑料，包含分布式功能的无数应用。具体来说，ROMP通过使用成熟的催化剂，通过张力环烯烃单体的链式生长，提供了各种工业相关的聚烯烃基材料。肯纳默团队将进行系统的合成、动力学和机理研究，以了解基本热力学原理以及催化剂和溶剂等关键条件如何最终决定各种环烯烃单体的反应性比率及其在生长的大分子链中的排序。该项目还将引入新的生物质基萜烯环烯烃，以提供ROMP中常用的环烯烃单体所不能提供的中等环应变的热力学谱。该研究团队将继续参与美国化学学会聚合物化学分部和聚合物材料科学与工程分部的学生分会，该分会是由佛罗里达农业和机械大学（FAMU）和佛罗里达州立大学R1研究型大学共同建立的。这个学生章节将汇集高度多样化的学生和教师，旨在研究聚合物科学。这个独特的平台还将用于促进研究生和本科生在领导力发展方面的成长，这两方面都是由外展和以佛罗里达为中心的以聚合物科学为中心的新会议的发展所控制的。本项目将重点阐明具有不同环应变能的单体开环复分解共聚热力学。在第一个目标中，对其环应变能（RSE）的微小变化高度敏感的低应变环戊烯单体的反应性比率将使用现代综合方法确定。确定的参数将与聚合物微观结构内的单体排序相关联，作为热力学原理（单体浓度、化学计量和温度）的函数。第二个目标将检查delta-蒎烯及其变体apopinene，它们具有介于ROMP中通常使用的高应变和低应变单体之间的rse。基本热力学研究和这些萜烯基单体之间以及与低/高RSE单体的共聚也将进行探索。最后，最后一个具体目标将通过研究高应变和低应变单体组合来推动rse之间差异的极限。这样的调查有潜力交替和块状测序策略。总之，这些研究有可能为从现成的环烯烃单体中合理设计共聚物提供指导原则；总的来说，有可能揭示适用于开环聚合（ROMP）的基本原理，从而对聚合物化学产生重大的长期科学影响。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。