Collaborative Research: Polar-Polyolefin Block Copolymers via MILRad Functionalization: A Platform for Amphiphilic Nanostructured Material Synthesis

在化学系大分子、超分子和纳米化学项目的支持下，休斯顿大学的Eva Harth教授和卡内基梅隆大学的Krzysztof Matyjaszewski教授的目标是探索在塑料材料的聚合物合成过程中产生锚定单元的能力，并使用这些“插件”单元作为活化剂进一步修饰聚合物。这两步过程将导致聚合物链由两个结构和性质截然不同的段（或块）组成。每个块的独特极性和溶解度使得聚合物可以用作两种不相容塑料材料之间的“缝线”，或者形成球体、蠕虫和圆盘形状的三维结构。这两个研究团队在各自的专业领域相互补充，预计将协同工作，建立化学途径来合成这些二嵌段共聚物，并研究它们的特殊性质。为了进一步提高二嵌段聚合物制备的便捷性和实用性，将研究一种自动化连续流方法。这项研究的结果有望提高人们对如何将极性链和非极性链结合起来以获得新材料的认识，并将成果传达给公众和科学界。该项目将通过培训研究生和本科生，包括来自代表性不足群体的学生，在聚合物化学、有机金属化学和分析的许多方面，帮助为聚合物工业准备一支熟练的劳动力队伍。具体来说，两个团队将合作探索基于新方法的嵌段共聚物和纳米结构合成，包括一种新的自由基和自旋捕获能力，将烯烃、丙烯酸和环氧乙烷段整合到一个聚合物结构中。作为聚合途径的一部分，通过金属插入/光引发自由基聚合产生宏观自由基将被用于制备中间体，通过原子转移自由基聚合和氮氧化物介导聚合促进可控自由基聚合。该策略可能通过链延伸为极性聚烯烃二嵌段和三嵌段共聚物开辟了一条新途径，并有望为目前无法使用现有方法或只能通过多步骤方法获得的嵌段共聚物提供便利。聚合诱导的自组装过程和结晶驱动的自组装将作为由聚烯烃和聚丙烯酸酯组成的二嵌段和三嵌段形成纳米结构的潜在途径进行研究。连续流动化学将用于优化和扩大聚烯烃宏观引发剂的合成，并将用于支持多种含聚烯烃纳米结构的合成。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。

With the support of the Macromolecular, Supramolecular and Nanochemistry Program in the Division of Chemistry, Professor Eva Harth at the University of Houston and Professor Krzysztof Matyjaszewski at Carnegie Mellon University aim to explore the capabilities of generating anchor units in polymers of plastic materials during their synthesis and using these "plug-in" units as activators for further modification of the polymer. This two-step process will result in polymer chains that are composed of two segments (or blocks) of distinctly different structures and properties. The unique polarity and solubility of each block allows the polymer to be used as "stitches" between two immiscible plastic materials or to form 3-D structures in shapes of spheres, worms and disks. The two research teams complement each other in their areas of expertise and are expected to work synergistically to establish chemical pathways to synthesize these diblock copolymers and study their special properties. An automated continuous flow approach will be investigated to increase further the ease and practicability of diblock polymer preparation. The results of this research are expected to enhance knowledge in how to combine polar and non-polar chains to gain access to novel materials, and the accomplishments will be communicated to the public and scientific community. This project will help to prepare a skilled workforce for the polymer industry by training graduate students and undergraduates, including students from underrepresented groups, in many aspects of polymer chemistry, organometallic chemistry and analysis.Specifically, the two teams will collaborate to explore block copolymer and nanostructure synthesis based on new methods development, including a novel radical- and spin-trapping capability, to integrate olefin, acrylic and ethylene oxide segments into one polymeric architecture. The generation of macro-radicals through metal insertion/light-initiated radical polymerization as part of the polymerization pathway will be utilized to prepare intermediates to promote controlled radical polymerization via atom transfer radical polymerization and nitroxide-mediated polymerization. This strategy may open up a new avenue for polar polyolefin di-block and triblock copolymers via chain extension and is expected to provide convenient access to block copolymers not yet available using existing methodology or only available via multi-step approaches. Polymerization-induced self-assembly processes and crystallization-driven self-assembly will be investigated as potential approaches to form nanostructures from di- and triblocks composed of polyolefins and polyacrylates. Continuous flow chemistry will be used to optimize and scale up polyolefin macro-initiator synthesis and will be used in support of the synthesis of a diverse set of polyolefin-containing nanostructures.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.