Preparation of degradable aliphatic polyester elastomers with tunable strength and elasticity via photo-crosslinking

Degradable polyester elastomers are highly desirable for biomedical applications. Here, highly transparent and degradable aliphatic polyester elastomers were prepared using the ring-opening copolymerization (ROCP) of commercial monomers, followed by a photo-crosslinking process. A series of the semi-crystalline copolyester (PMBL-co-PBL-co-PCL) precursors with different molecular weights and pendent vinyl contents were synthesized by one-pot ROCP of alpha-methylene-gamma-butyrolactone (MBL), epsilon-caprolactone (epsilon-CL) and gamma-butyrolactone (gamma-BL). Then, UV irradiation was applied to photo-crosslink the precursors to obtain several elastomers. The obtained aliphatic polyester elastomers (CPEs) displayed excellent mechanical properties with high tensile strength (11.3 MPa), high elongation at break (1300%) and high elastic recovery (about 99% after 10 hysteresis cycles). In addition, the elastomer showed much better stability than uncrosslinked (co)polyesters, but maintained degradability in the basic aqueous solution, with similar to 30% of the mass loss in 1 M NaOH solution after 30 days. Through efficient ROCP, we demonstrated a strategy to prepare degradable CPEs bearing high strength, good elasticity, excellent resilience and degradation capability, which can serve as sustainable elastomers for various applications.