Fig. 3: Schemes of chemoenzymatic recycling of TDI-based polyether-polyurethane foam.

PU foam (A) as substrate and tin (II)-2-ethylhexanoate as catalyst (B) to generate intermediate products (C) subsequently converted by metagenomic urethanase (D) used by Bornscheuer et al. to yield final aromatic diamine (TDA). Reproduced with permission28. Copyright 2023, WILEY.