CO2‑incorporated polyols derived from waste PET for flexible polyurethane foam synthesis

Although polyurethane foams (PUFs) are versatile materials, their synthesis still relies heavily on petrochemically-derived polyols. Herein, we report a sustainable catalytic route to novel polyols via the Zn/Co-based double metal cyanide catalyzed copolymerization of propylene oxide and CO 2 using bis(2-hydroxyethyl) terephthalate (BHET) derived from waste polyethylene terephthalate (PET) as an initiator. The resulting PET–CO 2 polyols integrated rigid aromatic segments and carbonate linkages, enabling the fabrication of flexible PUFs with improved compressive performance compared to those prepared from conventional polyether and polycarbonate polyols. Compositional, spectroscopic, and thermal analyses confirmed the successful incorporation of CO 2 and BHET into the polyol structure. This dual valorization of waste PET and CO 2 provides an economically and environmentally viable pathway for the production of functional polyols, contributing to circular-economy-oriented PU production. • Dual valorization of CO 2 and waste PET achieved through DMC-catalyzed copolymerization. • PET–CO 2 polyols contained up to 30 mol% carbonate linkages from CO 2 incorporation. • Flexible PU foams exhibited ∼40% higher compressive strength. • This approach enables sustainable upcycling of CO 2 and waste PET into functional polyols.