Self-healing and biodegradable copolyesters synthesized from 2,5-furandicarboxylic acid applied as human skin

The new self-healing and biodegradable copolyesters, poly(ethylene-co-diethylene glycol adipate-co-furanoate) (PEAF), were synthesized from 2,5-furandicarboxylic acid, dimethyl adipate, diethylene glycol and ethylene glycol by transesterification and polycondensation. Their number average molecular weight ( M n ) varied from 49,400 g/mol to 71,500 g/mol while the polydispersity index ranged from 1.47 to 1.97. The study showed that by adjusting the proportion of adipate segments from 25 mol% to 65 mol%, the tensile modulus was found to be ranging from 4.95 to 0.29 MPa at room temperature, which was close to or even lower than the modulus of human skin. The excellent biodegradability of PEAFs was certified by the weight loss of 34.5% to 80.9% during enzymatic degradation. Finally, self-healing properties were also discovered in PEAFs and the fastest self-healing rate observed was 23.1 μm/h for PEAF-65 at 37 °C. Due to these outstanding properties, PEAFs absolutely possess the potential to be used as human soft tissues, electronic skin, human-machine interface and so on.