Singer Frances N, Deacy Arron C, McGuire Thomas M, Williams Charlotte K, Buchard Antoine
Department of Chemistry, University of Bath, Centre for Sustainable and Circular Technologies, Claverton Down, Bath, BA2 7AY, UK.
Department of Chemistry, University of Oxford, Chemistry Research Laboratory, 12 Mansfield Rd, Oxford, OX1 3TA, UK.
Angew Chem Int Ed Engl. 2022 Jun 27;61(26):e202201785. doi: 10.1002/anie.202201785. Epub 2022 May 5.
Chemical recycling of polymers to true monomers is pivotal for a circular plastics economy. Here, the first catalyzed chemical recycling of the widely investigated carbon dioxide derived polymer, poly(cyclohexene carbonate), to cyclohexene oxide and carbon dioxide is reported. The reaction requires dinuclear catalysis, with the di-Mg catalyst showing both high monomer selectivity (>98 %) and activity (TOF=150 h , 0.33 mol %, 120 °C). The depolymerization occurs via a chain-end catalyzed depolymerization mechanism and DFT calculations indicate the high selectivity arises from Mg-alkoxide catalyzed epoxide extrusion being kinetically favorable compared to cyclic carbonate formation.
将聚合物化学循环转化为真正的单体对循环塑料经济至关重要。在此，报道了对广泛研究的源自二氧化碳的聚合物聚（环己烯碳酸酯）进行的首次催化化学循环，将其转化为环氧环己烷和二氧化碳。该反应需要双核催化，双镁催化剂显示出高单体选择性（>98%）和活性（TOF = 150 h⁻¹，0.33 mol%，120 °C）。解聚通过链端催化解聚机制发生，密度泛函理论计算表明，与环状碳酸酯形成相比，镁醇盐催化的环氧化物挤出在动力学上更有利，从而产生了高选择性。
