CAREER: CAS: Highly Stable Depolymerizable Polymers with Tunable Thermal and Mechanical Properties as Sustainable Materials

About This Grant

NON-TECHNICAL SUMMARY Synthetic polymers, including rubber and plastics, are used in nearly every aspect of daily life. The dominance of synthetic polymers is largely driven by their excellent stability and versatile mechanical properties. However, due to their high durability, waste materials composed of these polymers have accumulated in the land and oceans, causing serious concerns for the ecosystem. In addition, since over 90% of these polymers are derived from finite fossil feedstocks, the production of these materials is unsustainable if they cannot be recycled and reused. This project seeks to address these challenges by developing recyclable polymers that can be broken down into the constituents (monomers) from which they are made. The recycled monomers can be reused to produce the polymers, allowing for a circular use of materials, which not only helps to preserve the finite natural resources used in plastics production, but also addresses the issue of unwanted end-of-life accumulation of plastic objects. Besides demonstrating the recycling of the polymers, the PI plans to tune the thermal and mechanical properties of the polymers to meet the needs of a variety of applications. This project will also contribute to education and broadened participation in materials science and sustainability through developing undergraduate and graduate courses, recruiting underrepresented minority researchers, and reaching out to local high schools and museums. A multimedia exhibition called “Polymers and Life”, which will include cards, videos and hands-on projects, will be developed in collaboration with the Akron Children’s Museum. TECHNICAL SUMMARY A promising solution to address the challenges in plastics sustainability is to replace current polymers with recyclable ones in order to achieve a circular use of materials. Despite the progress made thus far, few recyclable polymers exhibit the excellent thermal stability and high-performance mechanical properties of traditional polymers. This project aims to address those challenges by developing polymers that can undergo catalytic depolymerization to yield their constituent monomers. When the catalyst for depolymerization is absent or removed, the polymers will be highly stable and their thermal and mechanical properties can be tuned to meet the needs of various applications. The objectives of the research include design and synthesis of the polymers, demonstration of depolymerizability and stability, and establishment of structure–thermal property relationships and structure–mechanical property relationships. Research results will be incorporated into undergraduate and graduate courses. These courses are expected to bridge the knowledge gap between fundamental physical organic chemistry and materials science, integrate experimental and computational research, and enhance student awareness of sustainability. The proposed research will also provide opportunities to attract and nurture a diverse group of future scientists who can participate in research activities on sustainable polymers. In addition, demonstration materials based on the research findings will be developed for use in outreach efforts to local high schools and museums in order to inspire an interest in science in the younger generation. . 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.