Closed-loop recycling of polyurethane waste

The effective recycling of waste polyurethane foam (PUF) is essential for reducing environmental burden, preventing littering, and decreasing reliance on virgin resources. In this study, we developed a mild, solvent-assisted glycolysis strategy using polyether polyol and various small-molecule diols to achieve complete depolymerization of waste PUF. The resulting recycled polyols (RPs) exhibited excellent reactivity and compatibility, enabling direct reuse-without purification-in the synthesis of rigid polyurethane foam (RPUF) at a substitution level of up to 40 wt%. Comprehensive characterization confirmed that the mechanical and physical properties of the recycled RPUF were comparable to those of commercial products. Importantly, a cradle-to-gate life cycle assessment (LCA) was conducted, highlighting the minimal differences in environmental impacts of the process, with a focus on the limitations of the assessment, particularly in terms of global warming potential (GWP). This work provides important theoretical support for the industrialization of polyurethane waste recycling.