Synthesis of sustainable green bio-polycarbonates from bio-based feedstock and CO2 toward carbon-neutral goals: opportunities and challenges.

The growing challenges of plastic pollution, fossil resource depletion, and carbon emissions have accelerated the search for sustainable alternatives to polymers. This review focuses on the development of fully bio-based polycarbonates synthesized through the copolymerization of carbon dioxide (CO2) and renewable epoxides. A wide range of bio-feedstocks including plant oils, terpenes, lignocellulosic biomass, and industrial byproducts, are examined for their potential to serve as precursors for epoxide monomers. The effects of monomer structure on polymer properties and performance are discussed, along with pathways for post-polymerization modification to improve application-specific functionality. Various catalytic systems are critically analyzed, including both heterogeneous and homogeneous catalysts with a focus on their effectiveness and selectivity in polymerization. Applications of bio-based polycarbonates are explored in fields such as coatings, biomedical materials, adhesives, and their recycling pathways. Future directions emphasize the need for advanced catalyst design, AI manufacturing, and supportive policy frameworks to enable scalable and sustainable production. The integration of CO2 utilization with renewable feedstocks presents a compelling route toward circular and carbon-neutral materials.