Foam‐to‐Foam Recycling Potential of PU‐Foams by Integration of Amino Esters

Abstract The increasing market demand for flexible polyurethane foams (PUFs) is prompting the academic and industrial community to seek solutions for their end‐of‐life management. In this study, this issue is addressed by incorporating β‐amino ester (BAE) moieties into the foam structure. This addition results in flexible hybrid PU‐BAE foams that can be thermally reprocessed and chemically recycled, with cell sizes ranging from 780 to 990 µm and densities between 90 and 150 kg m⁻³. These foams demonstrate thermomechanical reprocessability, yielding stable PU‐BAE elastomers, with glass transition temperature values ranging from 14 to 25 °C. Stress relaxation experiments reveal remarkably fast relaxation times for these hybrid elastomers (23 s at 160 °C). Furthermore, a systematic investigation of the chemical recyclability of these foams via glycosylation is conducted under mild conditions, achieving complete disintegration within 20 min at 65 °C. Finally, the chemically recycled product is converted into a foam again, achieving a closed loop foam‐to‐foam recycling process. These findings indicate that the integration of BAE into PUFs leads to an enhanced chemical recycling rate, providing a promising avenue for addressing end‐of‐life concerns in PUF‐applications.