Synthesis and characterization of biodegradable and photocrosslinkable multi-block poly(ether-ester): Molecular-weight and component of the polyethylene glycol segment dependence

This work synthesized a series of biodegradable thermoplastic elastomer PBSFG via an esterification polycondensation reaction. The influence of the soft segment PEG molecular weight and component on the thermal behavior, mechanical property, and degradation performance of PBSFG were investigated. The results showed that the PEG component plays a major part in the properties of PBSFG. Upon reaching a PEG component concentration of 40% within PBSFG, the yielding phenomenon becomes imperceptible on the stress-strain curves, signifying the onset of a plastic-to-elastomer transition. In the case of PBSFG40-6k, a remarkable tensile strength of 23.5 MPa and an elongation at break measuring 576% were achieved, thereby displaying tensile properties on par with those of PBAT. Thanks to the unsaturated structure, the mechanical properties of PBSFG can be enhanced by UV irradiation. Finally, Candida cylindracea lipase catalytic degradation experiments showed that PBSFG is a biodegradable polyester, which is beneficial in reducing environmental plastic pollution.