Colorado State University
John K. Stille Chair in Chemistry, Millennial Professor of Polymer Science and Sustainability
Wednesday, October 2, 2019
Current practices in the generation and disposal of synthetic polymeric materials are largely unsustainable and also causing severe worldwide polymer pollution and enormous materials value losses to the economy. Several solutions have been intensively pursued to address this global challenge but the current solutions suffer from either significant materials value and quality losses or unintended environmental consequences. The development of chemically recyclable polymers that can be completely and repeatedly depolymerized back to their building-block monomers for virgin-quality polymer reproduction provides a practical approach to achieving a circular materials economy and addressing polymer pollution. However, realizing such sustainable polymers must meet three challenges: energy cost, depolymerization selectivity, and depolymerizability/performance tradeoffs.
Centering on addressing the above identified challenges, this presentation will describe recent advances made in this field. In particular, the seminar will focus on the chemical synthesis of stereoperfect, highly crystalline and high-molecular-weight bacterial polyesters with a closed-loop chemical life cycle, as well as the discovery of infinitely recyclable plastics that are not only thermally and mechanically robust to be practically useful but also thermally and/or chemically depolymerizable with quantitative selectivity for clean monomer recovery and polymer reproduction under cost-effective polymer production and deconstruction conditions.