Design and Optimization of Non-Fluorous CO2-Philic Polymers: FTIR and Phase Behavior Investigations

非氟亲 CO2 聚合物的设计和优化：FTIR 和相行为研究

• 批准号: 0207781
• 负责人: Christopher Roberts
• 金额: $ 16.22万
• 依托单位: Auburn University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-08-01 至 2006-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0207781&HistoricalAwards=false
• 关键词: Design; Optimization; Non; Fluorous; CO2

The application of CO2 to chemical processing continues to elicit significant interest, as CO2 generally poses fewer hazards than conventional organic solvents. At one time it was thought that CO2 could simply replace many organic solvents, but subsequent work showed that CO2 is a rather feeble solvent, and hence unrealistically high pressures are needed to dissolve compounds of interest. The discovery during the 1990's of "CO2-philes" suddenly rendered a number of applications technically possible, greatly raising interest in CO2 as a solvent. These new CO2-philes, primarily fluoropolymers, allowed a host of new applications for CO2, from heterogeneous polymerization to homogeneous catalysis. Although fluorinated amphiphiles were technically successful, their high cost renders the economics of a process unfavorable unless the ihCO2-philelo can be recycled at greater than 99% efficiency. Complicating matters further, recycle of additives from a high-pressure process is neither easy nor inexpensive. The drawbacks inherent to the useof fluorinated precursors have greatly inhibited the commercialization of most new applications for CO2, and thus the full promise of CO2-based technology has yet to be realized. The PI has investigated the design of non-fluorous CO2-philes. To date, he has used a set of simple heuristics to design three types of non-fluorous CO2- phile; he expects that others will ultimately be found, greatly broadening the applicability of CO2 as a solvent.The number of possible design variables (copolymer composition and topology) creates an impractically large program if we continue to synthesize and test all potentially useful structures. Further, conventional thermodynamic models are incapable of predicting the behavior of all of the possible permutations. Consequently, The PI will conduct a coordinated program between the University of Pittsburgh and Auburn University whose ultimate aim is to fully understand the effect of composition and topology on the phase behavior of our new CO2-philes in carbon dioxide. He will to combine targeted synthesis, measurement of selected thermophysical properties, high pressure FT-IR, and development of an accurate potential function from first principles to mathematically describe the thermodynamics of mixing of his materials with CO2. Success will allow himto numerically optimize the structure of non-fluorous CO2-philes.The program described herein involves a fully integrated project at both the University of Pittsburgh (E.J. Beckman, R.M. Enick, J.K. Johnson) and Auburn University (C.B. Roberts). The tasks to be performed at Auburn University (C.B. Roberts) include both phase behavior and FTIR studies, where high pressure IR measurements will be employed to evaluate the strength of specific interactions of CO2 with the Lewis base groups incorporated into our model polymers. The high pressure IR work provides both input to the synthetic design and the construction of an accurate potential model for CO2-polymer interactions.

二氧化碳在化学加工中的应用继续引起人们的极大兴趣，因为二氧化碳通常比传统有机溶剂造成的危害更少。一度人们认为二氧化碳可以简单地取代许多有机溶剂，但随后的研究表明二氧化碳是一种相当弱的溶剂，因此需要不切实际的高压来溶解感兴趣的化合物。 1990 年代“嗜二氧化碳分子”的发现突然使许多应用在技术上成为可能，极大地提高了人们对二氧化碳作为溶剂的兴趣。这些新的亲二氧化碳物质，主要是含氟聚合物，使二氧化碳有了许多新的应用，从多相聚合到均相催化。尽管氟化两亲物在技术上取得了成功，但其高成本使得工艺的经济性不利，除非 ihCO2-philelo 能够以高于 99% 的效率回收。使问题进一步复杂化的是，从高压工艺中回收添加剂既不简单也不便宜。使用氟化前体所固有的缺点极大地抑制了大多数二氧化碳新应用的商业化，因此基于二氧化碳的技术的全部前景尚未实现。 PI 研究了非氟 CO2 亲和体的设计。迄今为止，他已经使用一组简单的启发法设计了三种类型的非氟亲二氧化碳剂：他预计最终会发现其他的结构，从而大大拓宽二氧化碳作为溶剂的适用性。如果我们继续合成和测试所有潜在有用的结构，可能的设计变量（共聚物组成和拓扑结构）的数量会创建一个不切实际的大型程序。此外，传统的热力学模型无法预测所有可能的排列的行为。因此，PI 将在匹兹堡大学和奥本大学之间开展一项协调计划，其最终目标是充分了解成分和拓扑结构对二氧化碳中新型亲二氧化碳物质相行为的影响。他将结合目标合成、选定热物理性质的测量、高压 FT-IR 以及根据第一原理开发精确势能函数，以数学方式描述其材料与 CO2 混合的热力学。成功将使他能够在数值上优化非氟亲二氧化碳分子的结构。本文描述的计划涉及匹兹堡大学（E.J.贝克曼、R.M.埃尼克、J.K.约翰逊）和奥本大学（C.B.罗伯茨）的完全集成项目。奥本大学（C.B. Roberts）要执行的任务包括相行为和 FTIR 研究，其中将采用高压红外测量来评估 CO2 与纳入模型聚合物中的路易斯碱基团的特定相互作用的强度。高压红外工作为合成设计和构建 CO2-聚合物相互作用的准确潜在模型提供了输入。