Faculty Affairs and Academic Programs
Ty Christoff-Tempesta
Engineering and Computer Science
Materials Science and Engineering
UC Irvine
Unzip, Rebuild, Repeat: Sustainable and Circular plastics alternatives designed to deconstruct and reassemble
Global plastics production is projected to reach 25 billion tonnes by 2050, but only 14% of plastics waste is effectively recycled as commodity plastics and renewable alternatives are not designed for circularity. Chemical recycling offers a promising solution to address this challenge by deconstructing the polymers underlying plastics into their molecular building blocks and resynthesizing new materials with retained or tailored properties. In this proposal, we address two outstanding, fundamental questions: (1) how can the defining chemical features of polymer classes enable polymers to ‘unzip’ to their building blocks with heat alone; and (2) how can the complex chemical features of renewable molecules be used in polymer design to both lower thermal deconstruction temperatures and retain plastic-like properties? To answer these questions, we will synthesize and characterize 16 thermally deconstructable polymer classes to determine how variations in reactive group chemistries, which bond small molecules into polymers, affect deconstruction behaviors. In parallel, we will leverage a machine-learning framework to design ~40 thermally deconstructable polymers with chemically diverse side groups, which protrude from polymer chains to manipulate both material properties and deconstruction outcomes. Identifying how side group features affect polymer deconstruction will enable the development of new materials that use renewable feedstocks to intrinsically lower energy requirements for chemical recycling. In total, establishing fundamental principles relating monomer design to deconstruction thermodynamics and kinetics will enable circular and renewable plastics alternatives.
