2001 Technology for a Sustainable Environment: NSF/EPA Partnership for Environmental Research: Design and Optimization of Non-Fluorous CO2-Philic Polymers (TSE01-F)

2001 可持续环境技术：NSF/EPA 环境研究伙伴关系：非氟亲二氧化碳聚合物的设计和优化 (TSE01-F)

• 批准号: 0124400
• 负责人: Eric Beckman
• 金额: $ 36万
• 依托单位: University of Pittsburgh
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-09-15 至 2005-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0124400&HistoricalAwards=false
• 关键词: 2001; Technology; Sustainable; Environment; NSF

AbstractCTS-012440Beckman, EricU of PittsburghDesign and Optimization of Non-Fluorous CO2-Philic Polymers 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 "CO2-phile" can be recycled at greater than 99% efficiency. The drawbacks inherent to the use of 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. Consequently, we have investigated the design of non-fluorous CO2-philes. First, a set of thermodynamic heuristics for the design of non-fluorous CO2-philes was developed. The applicability of these rules-of-thumb was demonstrated by the design of poly(ether-carbonates), polymers that exhibit lower miscibility pressures in CO2 than perfluoropolyethers and are biodegradable. The method of synthesis of these materials readily allows generation of surfactants and other functional molecules, opening the economical use of CO2 to a variety of processes. To date, we have used our simple heuristics to design three types of non-fluorous CO2-phile; we expect 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, we propose to conduct a program 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. We propose 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 our materials with CO2. Success will allow us to numerically optimize the structure of non-fluorous CO2-philes.Research at the University of Pittsburgh will focus on the synthesis of model materials, investigation of phase behavior, and creation of a thermodynamic model that describes the effects of molecular structure on phase behavior. These tasks will be coordinated with research underway at Auburn University (C.R. Roberts), 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 input both to the synthetic design and the construction of an accurate potential model for CO2-polymer interactions.

摘要 CTS-012440Beckman，匹兹堡的 EricU 非氟亲 CO2 聚合物的设计和优化 CO2 在化学加工中的应用继续引起人们的极大兴趣，因为 CO2 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是成功的，但它们的高成本使得工艺的经济性不利，除非“亲二氧化碳亲和物”能够以高于 99% 的效率回收。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。因此，我们研究了非氟亲二氧化碳分子的设计。首先，开发了一套用于设计非氟二氧化碳亲和物的热力学启发法。这些经验法则的适用性通过聚醚碳酸酯的设计得到了证明，这种聚合物在二氧化碳中的混溶压力比全氟聚醚低，并且可生物降解。这些材料的合成方法很容易生成表面活性剂和其他功能分子，从而为各种工艺提供了二氧化碳的经济使用。迄今为止，我们已经使用简单的启发法设计了三种类型的非氟亲二氧化碳物质：我们预计最终会发现其他材料，从而大大拓宽二氧化碳作为溶剂的适用性。 如果我们继续综合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）的数量会产生一个不切实际的大程序。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，我们建议开展一项计划，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分子相行为的影响。我们建议将目标合成、选定热物理性质的测量、高压 FT-IR 以及根据第一原理开发的精确势函数结合起来，以数学方式描述我们的材料与 CO2 混合的热力学。成功将使我们能够在数值上优化非氟亲二氧化碳分子的结构。匹兹堡大学的研究将集中于模型材料的合成、相行为的研究以及描述分子结构对相行为影响的热力学模型的创建。这些任务将与奥本大学 (C.R. Roberts) 正在进行的研究相协调，其中将采用高压红外测量来评估 CO2 与纳入我们的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。