Ryan Clarke
Speaker's Institution
Colorado State University
4:00 PM
Chemistry A101
Mixer Time
3:45 PM
Mixer Time
Chemistry B101E
Calendar (ICS) Event
Additional Information

Research Seminar Abstract

Roughly 300 million tons of plastic enters the global economy each year. Each of these serve specific, property-based purposes in commodity materials. Most of these commercial plastics are composed of more than one polymer, adding complexity of post-consumer separation. Minimizing the material diversity in our economy is crucial, as recycling these multi-polymeric materials is costly and time inefficient when compared using landfills and incineration. One proposed solution is to employ homopolymer thermoplastic elastomers. These materials, when synthesized by a dynamic metallocene catalyst system, exhibit tunable thermal and mechanical properties and offer a viable solution to excessive plastic waste feedstocks. Investigations into the synthesis of stereoblock polypropylene thermoplastic elastomers have taken place over 6 decades, leading to current investigations by the Rieger group. To synthesize high-melting, elastic polypropylene and address the lack of stereocontrol in homopolymer stereoblock growth, dynamic dual-site metallocene catalysts are employed under manipulated reaction conditions. The mechanistic interplays of interconverting chelate ring conformers, polymer chain migration, and chain-end epimerization towards varying polypropylene isotactic pentad contents will be discussed.


Macromolecules 2018, 51 (3), 914-929

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