With this award, the Macromolecular, Supramolecular and Nanochemistry Program in the Division of Chemistry is funding Professor Chuanbing Tang of the University of South Carolina and Professor Stephen L. Craig of Duke University to develop a new class of polymers (plastics) that respond to specific types of stress. Synthetic polymers are versatile, processable, light weight, and have tunable mechanical properties, making them useful in everyday life. These metal-containing polymers made by the Tang group are used to make polymer materials that respond to physical pressures but are stable at high temperatures. The team's research explores the design and potential uses of mechanochemically-controlled plastics. Such plastics may be recycled by physical manipulation rather than re-melting, ultimately resulting in energy-savings during reuse. Outreach activities include the Chem-STAR program that provides research resources to primarily undergraduate institutions in the Raleigh-Durham area. Economically disadvantaged and minority students are also mentored and exposed to cutting-edge research through American Chemical Society Project SEED summer research program at the University of South Carolina.
This project is focused on developing synthetic approaches toward main-chain metallocene-containing polymers and studying their mechanochemical reactivity. The research plan utilizes ring-opening metathesis polymerization to synthesize well-defined main-chain metallocene polymers and copolymers. Experimental characterization of metallocene mechanochemistry is carried out through a combination of state-of-the-art techniques in polymer sonochemistry and single molecule force spectroscopy. Metallocene lability in polymers is further investigated using computational models that simulate forces applied at the molecular level. Mechanistic studies are conducted in order to elucidate the relative contribution of peeling versus shearing at the molecular scale. The overarching goal of this work is to understand the mechanisms and structure-activity relationship underlying the highly selective mechanochemical scission of metal-cyclopentadienyl bond. This work has the potential to develop synthetic polymers that are mechanically responsive and thermally stable, both of which are important for reusability and recyclability of most commodity polymers.
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.
