Efficient and Selective Chemical Recycling of CO2‐Based Alicyclic Polycarbonates via Catalytic Pyrolysis

作者：Yu Yan; Gao Bang; Liu Ye; Lu XiaoBing

来源：Angewandte Chemie, 2022, 134(34).

DOI：10.1002/ANGE.202204492

• Carbon Dioxide
• Epoxides
• Polycarbonates
• Recycling
• Salen

Chemical recycling of polymers to their constituent monomers is the foremost challenge in building a sustainable circular plastics economy. Here, we report a strategy for highly efficient depolymerization of various CO2‐based alicyclic polycarbonates to epoxide monomers in solvent‐free conditions by a simple CrIII‐Salen complex mediated catalytic pyrolysis process. The chemical recycling of the widely studied poly(cyclohexene carbonate) exhibits excellent reactivity (TOF up to 3000?h?1, 0.1?mol?% catalyst loading) and high epoxide monomer selectivity (>99?%). Mechanistic investigation reveals that the process proceeds in a sequential fashion via a trans‐carbonate intermediate.(#br)The catalytic pyrolysis of various CO2‐based polycarbonates in bulk recovers epoxide monomers quantitatively using a simple CrIII‐Salen catalyst. It even proceeds very efficiently for chemical recycling of poly(cyclohexene carbonate) from a plastic waste mixture and thus provides a closed‐loop approach towards a circular plastic economy in applications of CO2‐based polycarbonates.

• 单位
  精细化工国家重点实验室; 大连理工大学