Fuchs Martin, Walbeck Marcel, Jagla Eveline, Hoffmann Alexander, Herres-Pawlis Sonja
Institut für Anorganische Chemie, RWTH Aachen University, Landoltweg 1 A, 52074, Aachen, Germany.
Chempluschem. 2022 May;87(5):e202200029. doi: 10.1002/cplu.202200029. Epub 2022 Mar 25.
Our previously published non-toxic guanidine carboxy Zn catalysts, suitable for lactide ring opening polymerisation (ROP) under industrially preferred melt conditions, have been tested towards the alcoholysis of renewable polyesters. A structure-reactivity relationship has been found for the methanolysis of PLA in anhydrous THF, dependent on the substituents introduced at the ligand backbone. Using the unsubstituted "TMGasme" catalyst C2, a polyester conversion of 41 % was reached after 5 h at 60 °C. Introducing an electron density donating -NMe group at the ligand (C3) caused and increase in catalyst activity, resulting in a PLA conversion of 72 %. Hence, C3 was further tested, stressing the industrial applicability of PLA chemical recycling. Catalyst recycling, process scale up as well as solvent free alcoholysis, with full degradation in the PLA melt after 1 h, were demonstrated, allowing for the implementation of a circular (bio)plastics economy promoted by these catalysts.
我们之前发表的无毒胍基羧基锌催化剂适用于在工业上更青睐的熔融条件下进行丙交酯开环聚合（ROP），现已针对可再生聚酯的醇解进行了测试。对于在无水四氢呋喃中聚乳酸（PLA）的甲醇解，已发现一种结构-反应性关系，该关系取决于在配体主链上引入的取代基。使用未取代的“TMGasme”催化剂C2，在60°C下反应5小时后，聚酯转化率达到41%。在配体上引入供电子的-NMe基团（C3）会提高催化剂活性，使PLA转化率达到72%。因此，对C3进行了进一步测试，强调了PLA化学回收的工业适用性。展示了催化剂的循环利用、工艺放大以及无溶剂醇解，在PLA熔体中1小时后可实现完全降解，从而能够实现由这些催化剂推动的循环（生物）塑料经济。
