Seminar: Dr. Thomas Epps, III, University of Delaware
From Biomass Waste to Performance-Advantaged Polymers: Efficient Routes to Lignin Valorization
Economic challenges continue to hamper the adoption of biobased polymers as alternatives to petroleum-based plastics. Generally, renewable polymers are too expensive due to the inherent variability in biobased feedstocks and the significant separation steps required to make purified monomer streams. Here, we demonstrate that materials with reproducible thermal and mechanical characteristics can be synthesized in a controlled and predictable manner from batches of monomers with complex and somewhat variable compositions, such as minimally processed bio-oils obtained from depolymerized lignin. As one example, we leveraged polymer structure-property relationships to fabricate high-performance pressure sensitive adhesives (PSAs) from compounds directly obtained from raw biomass (poplar wood) deconstruction. These PSAs, generated from biobased block copolymers, exhibited the nanoscale characteristics of conventional phase-separated materials and had peel forces and tack forces that were competitive with commercial tapes. As another example, we investigated the thermomechanical and environmental toxicity behavior of newly created bisguaiacol precursors and epoxy networks, for which the precursor compounds could be derived from lignin. These systems demonstrated drop-in potential, in both synthesis and materials properties, relative to petroleum-based analogues, yet most importantly, demonstrated reduced negative environmental impacts when screened by several common toxicity assays. In the above cases we employed raw biomass as our feedstock; however, we have recently demonstrated the versality of our strategy by expanding our feedstocks to other commercial scale inputs and waste streams.
Thomas is the Thomas and Kipp Gutshall Professor of Chemical & Biomolecular Engineering at the University of Delaware (UD) with a joint appointment in Materials Science & Engineering and an affiliated appointment in Biomedical Engineering. He also is the Director of the new Center for Research in Soft matter & Polymers (CRiSP). He joined UD in 2006 after a stint as a National Research Council Postdoctoral Fellow at NIST. His research interests include nanostructured assemblies for targeted drug delivery and gene therapy, polymeric materials for bio-separation and ion-conduction membranes, nanostructured soft materials from biobased feedstocks, and polymer films for nanotemplating. Prof. Epps has received several honors and awards including: the John H. Dillon Medal from APS (2016); the Owens-Corning Early Career Award from AIChE (2015); named a Kavli Fellow by the National Academy of Sciences (2014); the Sigma Xi Young Investigator Award (2014); the Martin Luther King, Jr. Visiting Professorship at MIT (2012); the Thomas & Kipp Gutshall Professorship at UD (2012); the UD Alison Society, Gerard J. Mangone Young Scholars Award (2011); the DuPont Young Professor Grant Award (2010); the Presidential Early Career Award for Scientists and Engineers (PECASE) (2009); the Air Force Young Investigator Award (2008); the National Organization for the Professional Advancement of Black Chemists and Chemical Engineers (NOBCChE) Lloyd N. Ferguson Young Scientist Award (2007), and a National Science Foundation (NSF) CAREER Award (2007) among others. Prof. Epps also is active in the American Chemical Society (ACS Board of Directors Development Advisory Board), American Institute of Chemical Engineers, American Physical Society (Polymers Division), and Sigma Xi. He was elected a Fellow of the American Physical Society in 2017 and a Fellow of the Royal Society of Chemistry (FRSC) in 2018. He is a member of the Department of Energy Basic Energy Sciences Advisory Committee (BESAC) and an associate editor for Science Advances.