%0 Journal Article
%A Nemi Vora
%A Peter R Christensen
%A Jérémy Demarteau
%A Nawa Raj Baral
%A Jay D Keasling
%A Brett A Helms
%A Corinne D Scown
%B Science Advances
%D 2021
%G eng
%N 15
%P eabf0187
%R 10.1126/sciadv.abf0187
%T Leveling the cost and carbon footprint of circular polymers that are chemically recycled to monomer
%U https://www.science.org/doi/10.1126/sciadv.abf0187
%V 7
%8 09/2021
%! Sci. Adv.
%X <p>Mechanical recycling of polymers downgrades them such that they are unusable after a few cycles. Alternatively, chemical recycling to monomer offers a means to recover the embodied chemical feedstocks for remanufacturing. However, only a limited number of commodity polymers may be chemically recycled, and the processes remain resource intensive. We use systems analysis to quantify the costs and life-cycle carbon footprints of virgin and chemically recycled polydiketoenamines (PDKs), next-generation polymers that depolymerize under ambient conditions in strong acid. The cost of producing virgin PDK resin using unoptimized processes is ~30-fold higher than recycling them, and the cost of recycled PDK resin ($1.5 kg−1) is on par with PET and HDPE, and below that of polyurethanes. Virgin resin production is carbon intensive (86 kg CO2e kg−1), while chemical recycling emits only 2 kg CO2e kg−1. This cost and emissions disparity provides a strong incentive to recover and recycle future polymer waste.</p>