Transition Metal-Catalyzed Carbonylative Polymerizations

Title: Transition Metal-Catalyzed Carbonylative Polymerizations

Speaker: Li Jia(Department of Polymer Science, University of Akron)

Time: 15:00 pm, November 12, 2018
Location: Room 401,BILD 911,  Dushu Lake Campus


Abstract:
Millions of tons of plastics are produced globally each year and disposed after use. The persistence of the plastic items in the environment has created a plastic crisis. To make plastics more degradable in the environment, functional groups have to be present in the polymer backbone. Transition metal-catalyzed carbonylative polymerization (COP) is a powerful method for synthesis of a wide range of polymers with carbonyl groups in the backbone (for example, eqs 1 and 2). The polyketones are photodegradable, and the polyesters are hydrolytically degradable. COPs of heterocycles require an acyl-Co(CO)4 (eq 1), while COP of alkenes typically is catalyzed by Pd or less commonly Ni catalysts (eq 2).

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The cobalt catalyst has inherent limitations. To overcome the limitations, our group has explored zwitterionic nickel complexes isoelectronic to the cobalt catalyst in the last few years. This presentation will discuss the evolution of 4 generations of such nickel catalysts.The newest generation catalyzes both COP of cyclic ethers and COP of ethylene. In addition, it acts as a novel, unique dual-site catalyst for COP of ethylene together with cyclic ethers. Both segmented copolymer and randomly distributed copolymer can be synthesized. The former is a thermoplastic elastomer, and the latter is a thermoplastics. The zwitterionic design principle of Ni(II) catalysts has been validated.


Biography:
Dr. Li Jia received his B.S. degree from Lanzhou University in 1991, and Ph.D. degree from Northwestern University in 1996 (advisor: Professor Tobin J. Marks). He worked as a postdoctoral fellow with Professor Richard A. Andersen at University of California, Lawrence Berkeley Laboratory during 1996-1998, and was an assistant professor at Department of Chemistry in Lehigh University during 1998-2005. Then he worked for Rohm and Haas Electronic Materials as a senior scientist during 2005-2007. Dr. Jia joined the University of Akron as an assistant professor in Department of Polymer Science in 2007, and was promoted to associate professor in 2011 until now. His research interests include: supramolecular elastomers, rubber reinforcement, and metal-catalyzed polymerizations. Other research specialties include polymer and organic conductors, photolithography materials, colloidal self-assembly, and soft lithography. He won  Lindback Minority Junior Faculty Award in 2000, DuPont Young Investigator Award in 2001 and NSF CAREER Award in 2002.