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

非技术摘要：聚合物的可持续性既受其生产中使用的化学原料的影响，也受材料处置的影响。大多数塑料是从烯烃中合成的，这些原料可以从石油或可再生资源中提取。然而，这些聚烯烃是耐用材料，导致塑料垃圾堆积，从而威胁到全球环境和国家利益。这项工作描述了二氧化碳在聚合物结构中的包含，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，在聚合物链中加入二氧化碳可提高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，该项目通过让不同年龄段和人口统计的学生参与有针对性的研究生、本科生和高中研究项目，扩大了研究的参与度。将与当地公立学校一起实施关于回收的教育项目，以提高公众对塑料垃圾管理和可持续做法的理解。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造重新用途的塑料物品。技术摘要：这个以可持续发展为重点的项目的目标是解决在控制来自烯烃和二氧化碳的共聚物的热和机械性能方面的挑战。该项目的成果将促进1，3-丁二烯和二氧化碳可降解共聚物的合成，以操纵其微观结构、立体化学和官能化。聚合物微结构的支化将随着共轭加成和开环传播机制的变化而变化。立体选择性催化将赋予聚合物链一定的规整性，并对其进行光谱表征。提出了密集官能化结构的正交后聚合修饰，以从单一材料平台产生不同范围的产品。系统地合成上述材料并量化它们的热和机械性能将使人们能够详细地了解结构-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，以获得对聚合物链动力学和表面相互作用的全面了解。这一奖项反映了NSF的法定使命，通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为是值得支持的。

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.