Hydrolytically Stable\nDual-Dynamic Polyurethane Networks\nfrom Furfural

Dynamic polymer networks (DPNs) fabricated from renewable\nresources\nare being actively sought, ideally with recyclability and degradability.\nFurfural is a high-production-volume chemical, and most furfural-based\nDPNs contain acetals or imines, which are reported to be unstable\nunder hydrolytic conditions. Herein, a furfural-based diol (FAH) containing\na dynamic S,S-acetal group was prepared as an efficient chain extender\nand cross-linker for fabricating dual-dynamic polyurethane networks\n(PUNs). The structure of oligomeric diols (PEG, PTHF) and the ratios\nof FAH and bismaleimide were efficient tools to tune the mechanical\nproperties from elastomers to rigid plastics with strength over 55\nMPa. The dual-dynamic PUNs were featured with excellent stability\nduring thermal reprocessing and hydrolytic incubation in 1 M HCl or\n1 M NaOH solutions for up to 10 days, while solvent-assisted degradation\ncan be readily achieved by refluxing in DMF or DMSO. This study represents\na viable strategy to achieve furfural-based recyclable polyurethanes\nwith hydrolytic stability and solvent-assisted degradability.