Front Cover: Open Loop Recycling – Guanidine Iron(II) Polymerization Catalyst for the Depolymerization of Polylactide (Chem. Asian J. 5/2023)

Understanding structure–activity relationships: iron(ii) complexes of “Legacy Guanidines” as catalysts for the synthesis of polylactide

“…With a k app of 0.0050 ± 0.0005 min −1 it has a comparable activity to [Fe(TMG5NMe 2 asme)Cl 2 ] with a k app of 0.0048 min −1 under the same reaction conditions. 44 The complete depolymerization of PLA to methyl lactate could not be observed (see Fig. S70 †).…”

“…Therefore, and to investigate whether the trend found for the polymerization can be transferred to the depolymerization, initial tests using C2-C6 for the methanolysis of PLA were performed (see Table 6). Choosing the same conditions as in previous publications 43,44 allows a comparison of C2-C6 with other catalysts: PLA was depolymerized at 60 °C using 1 mol% catalyst, 7.13 equivalents MeOH and THF as solvent. The conversion of internal methine groups (X int ), the selectivity towards methyl lactate (MeLA) (S MeLA ) and the yield (Y MeLA ) were calculated.…”

“…42 Initially studied for the zinc TMGasme complexes, 43 the complex [Fe(TMG5NMe 2 asme)Cl 2 ] was further investigated in the alcoholysis and aminolysis as a chemical recycling method for PLA. 44 The catalyst depolymerizes PLA to methyl lactate (MeLA) in the presence of methanol at 60 °C within 24 h completely.…”

Opportunities and Challenges of Establishing a Regional Bio‐based Polylactic Acid Supply Chain

“…[76] As very recent example for new avenues of upcycling, the aminolysis of PLA to benzyl lactamide was reported. [77] Life cycle assessment of different PLA recycling technologies showed lower environmental impacts compared to incineration. In the publication of Maga et al 2019, [78] the global warming impact was determined for different recycling technologies (i.e., mechanical, chemical, and solvent-based recycling).…”