The advent of recyclable CO2-based polycarbonates

Abstract

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 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, which 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.