CAS: New Catalytic Processes for Polyolefin Sustainability and Waste Utilization

通过这个奖项，化学系的化学催化项目支持了马里兰大学化学与生物化学系的Lawrence R. Sita教授的研究。Sita教授和他的研究团队正在开发新的聚合催化系统，将丰富而廉价的原料化学品转化为具有明确和可控分子结构的新型聚烯烃材料。用这种新催化剂体系制备的聚合物被设计用于添加到现有的聚烯烃废料中，以提高转化为二次或多用途聚合物产品的效率，提高商业价值。社会对塑料的依赖带来了每年超过4亿磅的塑料废物被引入环境的重大惩罚。Sita研究小组正致力于寻找解决这一问题的方法，并设计新的聚烯烃材料，以替代比聚烯烃对环境影响更严重的塑料。该项目为不同群体的本科生和研究生提供教育和培训，使他们成为可持续科学政策的下一代科学家和领导者。外展活动包括一吨塑料回收挑战，让小学生和高中生更广泛地了解社会面临的塑料废物问题。通过该项目开发的新发明、技术和产品对聚合物科学和技术具有潜在的重大长期影响。Sita教授和他的研究小组正在开发构型稳定、对映体富集的过渡金属配合物，作为烯烃和非共轭二烯的对映体和立体选择性活性配位链转移聚合（LCCTP）、共聚合和环聚合的明确催化剂。这些新的催化工艺提供了具有技术相关物理性质的新型高度立体规则聚烯烃。各种光谱方法和同位素标记的配合物和单体正在被用于了解对映体和立体选择性LCCTP的机理，以进一步优化这些体系。立体选择性LCCTP正在指导设计和生产具有良好定义的新型聚烯烃嵌段共聚物，这些共聚物在缩合状态下进行微相分离，可以用作塑料废物共混增容剂和性能改性剂。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 this award, the Chemical Catalysis Program of the Division of Chemistry is supporting the research of Professor Lawrence R. Sita of the Department of Chemistry and Biochemistry at the University of Maryland. Professor Sita and his research team are developing new catalytic systems for polymerization that convert abundant and inexpensive feedstock chemicals into new polyolefin materials with defined and controllable molecular structure. The polymers prepared with this new catalyst system are designed to be added to existing polyolefin waste to improve conversion to second- or multi-use polymeric products of increased commercial value. Society’s dependence on plastics comes with a significant penalty of more than 400 million pounds of plastic waste that is introduced into the environment each year. The Sita research group is focused on finding solutions to this problem and designing new polyolefin materials that can serve as replacements for plastics with more severe environmental impacts than polyolefins. This project is providing education and training for a diverse group of undergraduate and graduate students, as the next generation of scientists and leaders for sustainable science policy. Outreach activities include a one-ton plastic recycling challenge to engage elementary and high school students in a broader understanding of the problems society faces with plastic waste. New inventions, technologies, and products that are being developed through this project have potentially significant long term impacts on polymer science and technology. Professor Sita and his research group are developing configurationally-stable, enantio-enriched transition-metal complexes that function as well-defined catalysts for the enantio- and stereoselective living coordinative chain transfer polymerization (LCCTP), co-polymerization, and cyclopolymerization of olefins and non-conjugated dienes. These new catalyzed processes are providing novel classes of highly stereoregular polyolefins with technologically-relevant physical properties. A variety of spectroscopic methods and isotopically-labeled complexes and monomers are being used to understand the mechanism of enantio- and stereoselective LCCTP to further optimize these systems. Stereoselective LCCTP is guiding the design and production of new classes of well-defined polyolefin block copolymers that undergo microphase-separation in the condensed state and that can be used as plastic waste blend compatibilizers and property modifiers.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.