NSF Award
2400996
Supported by the Macromolecular, Supramolecular, and Nanochemistry (MSN) program in the Division of Chemsitry and Office of Integrative Activities (OIA), this HBCU-EiR (HBCU-Excellence in Research) award to Professor Hoyong Chung of the Florida A&M University (FAMU) will develop new degradable and recyclable bottlebrush polymers featuring sulfur containing chemical links. These new polymers will be synthesized using a highly efficient and controllable ring-opening metathesis polymerization (ROMP). The new polymer will be designed to degrade easily in acidic or basic water (hydrolysis). This polymer can be safely degraded in the natural environment, and if collected, these degraded fragments could serve as raw materials for synthesizing the original polymer. The new polymer will promote environmental sustainability by incorporating the conveniently and fully degradable new functional group into the polymer backbone. This research project will enhance education for minority K-12 students, undergraduate students, and graduate students in the field of polymers. For local minority K-12 students, a three-phase program will be implemented in collaboration with the College, University, and a regional science center. Underrepresented undergraduate students will have access to summer research programs in real-world laboratories. Targeted education for graduate students will empower them to achieve exemplary Ph.D. outcomes, serving as inspiration for other minority students.<br/><br/>The pressing issue of plastic waste has sparked a study aimed at developing degradable polymers by integrating heteroatom-based, carefully designed cleavage sites into the polymer backbone. This research utilizes sulfur to design and synthesize monomers and polymers containing unexplored functional groups. These novel functional groups are engineered to degrade under weak acidic/basic conditions, yielding precursors originally used for monomer preparation. As a result, an infinite closed-loop recyclability will be established, involving monomer → polymer → diamine → recycled monomer conversion. Moreover, this new bottlebrush polymer will exhibit multi-stimuli responsiveness (pH and temperature). Leveraging these features, small molecules can be released from the bottlebrush polymer with imaging guidance during polymer degradation. The first objective of the study entails establishing newly designed monomer and polymer synthesis methods, diversifying chemical structures, and conducting degradation and recyclability tests. In the second objective, a bottlebrush polymer will be synthesized from a linear polymeric backbone with an embedded ATRP initiator and a degradable linker via a "grafting from" approach. In addition to the cleavable linker, the novel bottlebrush polymer possesses thermo-responsive and pH-sensitive small molecule releasing features to achieve imaging-guided degradation functionality.<br/><br/>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.
