CAS: New Catalytic Processes for Polyolefin Sustainability and Waste Utilization

点击翻译按钮获取中文摘要

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.