TY - JOUR AU - Jérémy Demarteau AU - Alexander R Epstein AU - Peter R Christensen AU - Mark Abubekerov AU - Hai Wang AU - Simon J Teat AU - Trevor J Seguin AU - Christopher W Chan AU - Corinne D Scown AU - Thomas P Russell AU - Jay D Keasling AU - Kristin A Persson AU - Brett A Helms AB -

Footwear, carpet, automotive interiors, and multilayer packaging are examples of products manufactured from several types of polymers whose inextricability poses substantial challenges for recycling at the end of life. Here, we show that chemical circularity in mixed-polymer recycling becomes possible by controlling the rates of depolymerization of polydiketoenamines (PDK) over several orders of magnitude through molecular engineering. Stepwise deconstruction of mixed-PDK composites, laminates, and assemblies is chemospecific, allowing a prescribed subset of monomers, fillers, and additives to be recovered under pristine condition at each stage of the recycling process. We provide a theoretical framework to understand PDK depolymerization via acid-catalyzed hydrolysis and experimentally validate trends predicted for the rate-limiting step. The control achieved by PDK resins in managing chemical and material entropy points to wide-ranging opportunities for pairing circular design with sustainable manufacturing.

BT - Science Advances DA - 07/2022 DO - 10.1126/sciadv.abp8823 IS - 29 LA - eng N2 -

Footwear, carpet, automotive interiors, and multilayer packaging are examples of products manufactured from several types of polymers whose inextricability poses substantial challenges for recycling at the end of life. Here, we show that chemical circularity in mixed-polymer recycling becomes possible by controlling the rates of depolymerization of polydiketoenamines (PDK) over several orders of magnitude through molecular engineering. Stepwise deconstruction of mixed-PDK composites, laminates, and assemblies is chemospecific, allowing a prescribed subset of monomers, fillers, and additives to be recovered under pristine condition at each stage of the recycling process. We provide a theoretical framework to understand PDK depolymerization via acid-catalyzed hydrolysis and experimentally validate trends predicted for the rate-limiting step. The control achieved by PDK resins in managing chemical and material entropy points to wide-ranging opportunities for pairing circular design with sustainable manufacturing.

PY - 2022 ST - Sci. Adv. T2 - Science Advances TI - Circularity in mixed-plastic chemical recycling enabled by variable rates of polydiketoenamine hydrolysis UR - https://www.science.org/doi/10.1126/sciadv.abp8823 VL - 8 ER -