Function Meets Circularity: Metal–Ionomer Cross-Links Toughen and Recycle CO 2 -Derived Polymers

Designing polymers that combine performance with sustainability remains a critical challenge. Here, we report high-performance elastomers derived from CO₂ and biobased monomers that integrate both mechanical toughness and closed-loop chemical recyclability through a single material feature: dynamic metal-ionomer cross-links. These ABA block polymers, synthesized from ε-decalactone, δ-jasmolactone, CO₂, and bicyclic epoxides, incorporate abundant and inexpensive metal carboxylates (Na-(I), Zn-(II), and Al-(III)) into the midblock, forming reversible networks that enhance tensile strength by 150% while maintaining high strain at break (>1500%) and elastic recovery (>85%). The same cross-links act as built-in catalysts, enabling energy-efficient depolymerization of both polyester and polycarbonate domains at 200 °C, recovering the original monomers. This dual-function approach advances circular polymer design by combining enhanced performance with efficient, low-energy, closed-loop recycling.