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.

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通常比常规有机溶剂造成的危害更小。人们一度认为CO2可以简单地取代许多有机溶剂，但随后的工作表明，CO2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。在20世纪90年代发现的“亲CO2”突然呈现了一些应用技术上的可能性，大大提高了对CO2作为溶剂的兴趣。这些新的亲CO2分子，主要是含氟聚合物，允许CO2的许多新应用，从非均相聚合到均相催化。虽然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CO2物”可以以大于99%的效率再循环。使用氟化前体的固有缺点极大地抑制了CO2的大多数新应用的商业化，因此基于CO2的技术的全部前景尚未实现。因此，我们研究了非氟亲CO2分子的设计。首先，开发了一套用于非氟亲CO2分子设计的热力学计算方法。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，聚（醚-碳酸酯）是在CO2中表现出比全氟聚醚更低的溶解压力并且是可生物降解的聚合物。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CO2的经济用途。到目前为止，我们已经使用简单的化学方法设计了三种类型的非氟亲CO2试剂;我们预计最终会发现其他亲CO2试剂，从而大大拓宽CO2作为溶剂的适用性。 如果我们继续合成和测试所有可能有用的结构，可能的设计变量（共聚物组成和拓扑结构）的数量将产生一个不切实际的大程序。此外，传统的热力学模型不能预测所有可能的排列的行为。因此，我们建议进行一项计划，其最终目的是充分了解我们的新的CO2-亲在二氧化碳中的相行为的组成和拓扑结构的影响。我们建议结合联合收割机有针对性的合成，选定的热物理性能，高压FT-IR测量，并从第一原理的一个准确的潜在功能的发展，以数学描述我们的材料与CO2混合的热力学。成功将使我们能够在数值上优化非氟亲CO2分子的结构。匹兹堡大学的研究将集中在模型材料的合成，相行为的调查，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），其中将采用高压IR测量来评估CO2与并入到我们的模型聚合物中的刘易斯碱基团的特定相互作用的强度。高压IR的工作提供了输入的合成设计和建设一个准确的潜在模型CO2-聚合物的相互作用。