Enabling Polyolefin Circularity through Melt Functionalization and Upcycling
Abstract
Polyolefins represent the largest contribution to plastic production, use, and generated waste worldwide (e.g., 62% of plastics produced in the U.S. are polyethylenes and polypropylenes), yet their recycling rates are abysmally low (1-10% for various polyolefins in the U.S.). More efficient methods of recycling polyolefins have been underexplored, due to significant technological, scientific and economic challenges. Current recycling is limited by the inherent cost in and supply chain logistics of collecting, sorting and cleaning diverse plastic composition waste streams, the presence of additives, fillers and inks, and the downgrading of polymer properties during mechanical recycling. The lack of control over polymer architecture and molecular weight invariably results in recycled materials with inferior properties.
This presentation will discuss new strategies for recycling and reuse of polyolefin waste through industry-relevant melt-based functionalization processes followed by upcycling to new materials. Specifically, the formation of thermoset polyurethane networks was explored, in which the interplay of crystallization of the polymer and formation of a network architecture governed the resulting material properties. In addition, the use of melt oxidation as a route to functionalize polyolefins, revealing new material properties and enabling pathways to form more durable thermosets, was explored. These functionalization and upcycling routes thus offer promising alternatives for repurposing polyolefin waste, in which the creation of melt-processable thermoset polymers opens new applications for the materials.
Bio
Megan L. Robertson is the Neal R. Amundson Professor and Associate Chair for Faculty Development in the William A. Brookshire Department of Chemical and Biomolecular Engineering, as well as the Director of the Materials Science and Engineering Program, at the University of Houston. She is the project director for the recently awarded Welch Foundation Catalyst for Discovery Center for Plastic Circularity and the Circularity Lead for the University of Houston Energy Transition Institute. Dr. Robertson earned her PhD at the University of California, Berkeley and conducted post-doctoral research at the University of Minnesota. Her research interests span diverse areas including sustainable polymers derived from renewable resources, biodegradable polymers and polymer end-of-life processes such as recycling and upcycling, advanced resins for polymer composites, structure and dynamics of block copolymer micelles, antifouling polymers and polymer brushes, and thermodynamics of polymer blends. She is a Fellow of the American Chemical Society (ACS), recipient of the ACS Sparks-Thomas Award, current Past Chair of the ACS Polymeric Materials: Science and Engineering Division, and an Associate Editor for the journal Macromolecules.