The advent of recyclable CO2-based polycarbonates

Found in all sectors of applications, synthetic plastics have become ubiquitous and versatile materials in our modern life. However, most of them are produced from fossil resources and are responsible for a dramatic environmental pollution when not properly recycled/treated after utilization. Pushed by environmental incentives and legal obligations from the European Commission, there is an urgent need to reinvent the fabrication of plastics, ideally by exploiting raw biochemicals and waste effluents such as CO2, while making the plastics more easily degradable or recyclable. This review discusses the chemical recycling pathways of a family of more sustainable polymers, i.e. polycarbonates, that are prepared by valorizing raw CO2 as an inexhaustible, cheap and abundant C1-feedstock. In particular, this review draws briefly the fundamentals of the main synthetic approaches for the production of CO2-based polycarbonates by the direct copolymerization of CO2 with epoxides or by the (co)polymerization of CO2-based monomers. The most relevant chemical re-/up-cycling scenarios of the different classes of polycarbonates are then addressed to illustrate the potential of these products to design more sustainable materials.