Fabrication of Superinsulating Poly(Urethane‐Isocyanurate) Aerogels Derived from Upcycled Polycarbonate

Abstract Upcycling plastic waste into advanced functional materials is a sustainable approach to mitigate plastic accumulation and its associated environmental hazards. In this work, bisphenol‐A polycarbonate (BPA‐PC) is upcycled into an aromatic Mannich polyol (MP) via a simple one‐pot process combining organocatalyzed methanolysis followed by a Mannich reaction. MP further serves as a precursor for poly(urethane‐isocyanurate) (PUR‐PIR) aerogels. The resulting PUR‐PIR aerogels are prepared with different isocyanate indices and demonstrate low bulk densities (<195 mg cm ⁻³ ), and high specific surface areas (≈ 200 m ² g ⁻¹ ), along with outstanding mechanical performance, and ultralow thermal conductivity (≈ 17 mW m ⁻¹ K ⁻¹ ). Importantly, PUR‐PIR aerogels prepared from pristine or waste BPA‐PC exhibit comparable material performance. This work highlights the potential of upcycling plastic waste into superinsulating aerogels with tunable material properties.