Polyolefin Miscibility: Using Novel Chain Level Experiments to Create Miscible Blends

技术摘要。杰弗里·L·怀特教授的研究小组对聚烯烃混合物中复杂相行为的根本来源提出了新的见解。利用先进的具有链级分辨率的固态核磁共振实验，他的研究首次确定了多种聚烯烃混合物中的熵驱动相容。然而，链和组成单体结构之间的直接联系以及大分子中混合所需的正构型熵还没有建立起来，特别是对于商业上最相关的聚烯烃混合物。在下一个资助期，怀特教授和他的同事们将结合聚合物合成和热分析，对固体聚合物混合物使用最近开发的先进磁共振方法，以确定在各种聚丙烯、聚乙烯及其共聚物混合物中创建可混溶混合物所需的结构参数。总体而言，这些聚合物代表了最具经济价值的一类大分子。杰弗里·怀特教授和他的研究小组采取了一项长期战略，以了解如何创造具有经济应用吸引力的重要聚合物材料。他用先进的实验揭示了复杂有机材料最重要的基本方面，证明了令人满意的新材料实际上是如何从它们的单个成分形成稳定的结构的。这种被称为聚烯烃的有机聚合物对美国经济非常有价值，只有通过创造新材料才能进入新的市场和应用。怀特教授和他的研究小组利用在实验室中学到的技术，以及过去的工业经验，教育小学生和他们的老师科学对社会的好处。具体而言，怀特博士创建了一种名为“i-PROD”的新型教学工具，旨在激发年轻学生追求科学和工程职业的兴趣，并帮助解决未来国内技术竞争力的问题，这一点在最近的“美国竞争倡议”中得到了强调。

Technical Summary. Professor Jeffery L. White's research group has developed new insights into the fundamental origins of complex phase behaviors in mixtures of polyolefins. Using advanced solid-state NMR experiments with chain-level resolution, his research first identified entropically-driven miscibility in multiple polyolefin blends. However, the direct connections between chain and constituent monomer structure and required positive configurational entropies of mixing in macromolecules have not been established, particularly for mixtures of polyolefins that are most commercially relevant. During the next funding period, Professor White and coworkers will use recently-developed advanced magnetic resonance methods on solid polymer blends, in concert with polymer synthesis and thermal analysis, to identify the structural parameters needed to create miscible blends in various mixtures of polypropylenes, polyethylenes, and their copolymers. Collectively, such polymers represent the most economically valuable class of macromolecules.Non-Technical Summary. Professor Jeffery White and his research group have adopted a long-term strategy to understand how to create important polymer materials whose properties are attractive for economic applications. Using advanced experiments that unravel the most important fundamental aspects of complex organic materials, he has demonstrated how desirable new materials actually form stable structures from their individual components. This class of organic polymers, known as polyolefins, is extremely valuable to the U.S. economy, with new markets and applications accessible only through creation of new materials. Professor White and his research group use the techniques learned in the laboratory, as well as past industrial experiences, to educate elementary school students and their teachers on the benefits of science to society. Specifically, Dr. White has created a novel new teaching tool, called "I-PROD", to interest young students in pursuing science and engineering careers and help address future domestic competitiveness in technology, as highlighted in the recent American Competitive Initiative.