CAREER: CAS: Properties of Degradable Carbon Dioxide/Olefin Copolymers

非技术总结：聚合物的可持续性受到其生产中使用的化学原料和材料处理的影响。大多数塑料是由烯烃合成的，原料可以来自石油或可再生资源。然而，这些聚烯烃是耐用材料，造成了塑料废物的积累，从而威胁到全球环境和国家利益。这项工作描述了将二氧化碳包含到聚合物结构中，以及这种操作对材料的耐久性和性能的影响。通过使用二氧化碳作为原料，聚合物有可能消耗温室气体，而不是产生排放。此外，二氧化碳进入聚合物链赋予了可降解性和化学可回收性。该项目解决的基本问题是深入了解这些聚合物的结构如何影响其性能。此外，该项目还通过有针对性的研究生、本科生和高中研究项目吸引不同年龄段和人口统计学的学生参与，扩大了研究参与。为了提高公众对塑料废物管理和可持续做法的理解，将与当地公立学校一起实施回收教育计划。这些活动将包括为什么使用塑料，如何回收塑料，并使学生能够设计和制作重新利用的塑料物品。技术概述：这个以可持续发展为重点的项目的目标是解决控制由烯烃和二氧化碳衍生的共聚物的热性能和机械性能方面的挑战。该项目的研究结果将促进1,3-丁二烯与二氧化碳可降解共聚物的合成，以控制其微观结构、立体化学和功能。聚合物微观结构的分支会随着共轭加成和开环传播机制的变化而变化。立体选择性催化将使聚合物链具有弹性，并对其进行光谱表征。提出了密集功能化结构的正交聚合后改性，以从单一材料平台产生多种产品。系统地合成上述材料并量化其热性能和机械性能将使我们能够详细了解结构-性能关系。该研究计划将聚合物合成方法与光谱和计算技术相结合，以全面了解聚合物链动力学和表面相互作用。研究结果将增强对热性能和机械性能的控制，从而设计出与可持续性密切相关的有用聚合物材料。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。

NON-TECHNICAL SUMMARY:Polymer sustainability is impacted by both the chemical feedstocks used in its production and the disposal of the material. The majority of plastics are synthesized from olefins, feedstocks which can be derived from petroleum or renewable resources. However, these polyolefins are durable materials and have contributed to an accumulation of plastic waste, thereby threatening the global environment and national interests. This work describes the inclusion of carbon dioxide into the polymer structure and the impacts this manipulation has on the durability and properties of the materials. By using carbon dioxide as a feedstock, the polymers have the potential to consume greenhouse gas as opposed to generating emissions. In addition, the incorporation of carbon dioxide into the polymer chain imparts degradability and chemical recyclability. The fundamental issue this project addresses is the development of an in-depth understanding of how the structures of these polymers affect their performance. Furthermore, the project expands research participation by engaging various student age groups and demographics with targeted graduate, undergraduate, and high school research projects. Educational programs on recycling will be implemented with local public schools in order to improve public understanding of plastic waste management and sustainable practices. These activities will include why plastics are used, how they are recycled, and also enable students to design and make repurposed plastic objects.TECHNICAL SUMMARY:The objective of this sustainability-focused project is to address the challenges in controlling the thermal and mechanical properties of copolymers derived from olefins and carbon dioxide. The results of this project will advance the synthesis of degradable copolymers of 1,3-butadiene and carbon dioxide in order to manipulate the microstructure, stereochemistry, and functionality. The branching of the polymer microstructure will be varied as a function of the conjugate-addition and ring-opening propagation mechanisms. Stereoselective catalysis will impart tacticity to the polymer chains which will be characterized spectroscopically. Orthogonal post-polymerization modification of the densely functionalized structure is proposed to generate a diverse range of products from a single material platform. Systematic synthesis of the above materials and quantifying their thermal and mechanical properties will enable a detailed understanding of the structure-property relationships. The research plan merges methods of polymer synthesis with spectroscopic and computational techniques in order to acquire a holistic understanding of the polymer chain dynamics and surface interactions. The outcomes will empower control over the thermal and mechanical properties for designing useful polymeric materials closely relevant to sustainability.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.