# Function Meets Circularity: Metal–Ionomer Cross-Links Toughen and Recycle CO2‑Derived Polymers

## TL;DR

Scientists created tough, recyclable polymers from CO2 and natural materials using dynamic metal links that improve strength and allow recycling.

## Contribution

A dual-function approach using dynamic metal–ionomer cross-links to enhance polymer performance and enable closed-loop recycling.

## Key findings

- Polymers with 150% increased tensile strength and >1500% strain at break were achieved using dynamic metal cross-links.
- Original monomers were recovered through energy-efficient depolymerization at 200 °C using the same cross-links as catalysts.

## Abstract

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.