CAREER: Precise Synthesis of Polymers with Tunable Properties Through Stereocontrolled Olefin Metathesis

With the support of the Macromolecular, Supramolecular and Nanochemistry program in the Division of Chemistry, Quentin Michaudel of Texas A&M University is developing catalytic methods that will provide access to polymers with specific main-chain stereochemistry across several families of macromolecules. Stereochemistry is a branch of chemistry that is concerned with the study of 3D spatial arrangements of atoms in a molecule and the manipulation thereof. In this research, systematic studies will first be conducted to design efficient metal catalysts based on ruthenium and optimize reaction conditions. The developed synthetic routes will then be utilized to prepare a variety of stereoregular polymers, including industrially relevant polyesters and polycarbonates. Finally, the stereoregularity of polymers is to be correlated with their thermal and mechanical properties, as well as their degradability. The education plan will complement and amplify research efforts by broadening access to chemical education. Laboratory opportunities will be built for students with autism spectrum disorder. The research team will also foster awareness and inclusiveness through outreach with local support groups supporting autistic children and their families. The activities will include visits to the chemistry department at Texas A&M University and demonstrations focused on polymer science. Additional outreach will expose students with disabilities to science through collaboration with the Aggie ACHIEVE (academic courses in higher inclusive education and vocational experiences) program developed at the university. This project will focus on the development of stereocontrolled polymerizations utilizing ring-opening metathesis polymerization (ROMP) and acyclic diene metathesis (ADMET). A variety of monomers will be investigated in processes relying on a combination of stereoselective ruthenium catalysts and external stimuli (light, temperature, and exogenous reagents) to yield macromolecules with variable, yet predictable, cis:trans ratios of olefins in the main chain. The stimuli will provide an external lever with which to modulate the overall stereochemistry of the olefinic backbone through activation of either the repeating units, the catalyst, or the chain end. The outlined processes have the potential to provide a high level of control over the 3D architecture of many families of polymers and should permit systematic studies of the influence of alkene stereochemistry upon the thermal, mechanical, and optical/electronic properties of the synthesized soft materials. 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.