Amphiphilic and Chemically Recyclable CO₂-Based Polycarbonates from Biosourced Epoxides

Chemically recyclable polymers represent a long-term strategy to advance the circular material economy. The copolymerization of carbon dioxide (CO2) with epoxide has become a leading CO2 utilization technology, yet the resultant polycarbonates having optimal recyclability still face challenges in achieving structural versatility and controlled amphiphilicity. In this study, we present two novel types of completely recyclable polycarbonates synthesized from CO2 and biomass-derived epoxide substrates containing ester or amide functionalities. The preservation of a five-membered ring core ensures polymer-to-monomer recyclability, whereas the pendant amide group addresses the intrinsic hydrophobicity limitations of conventional CO2-based polycarbonates. Strategic postpolymerization modification to carboxylic acid and carboxylate ammonium salts in the polymer framework has significantly altered the thermal and surface properties, as well as solubility. This tunable amphiphilicity facilitates the spontaneous assembly of nanoparticles with exceptional colloidal stability in aqueous media. The synergy between CO2 utilization, biomass-derived feedstocks, and amphiphilicity establishes these functional polycarbonates as a versatile platform for developing sustainable biomaterials, particularly for applications in drug delivery systems and green nanomedicine.