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

Abstract

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 α-methylene-γ-butyrolactone (MBL), ε-caprolactone (ε-CL) and γ-butyrolactone (γ-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 $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.

Converting Unrefined Birch Suberin Monomers into Vitrimer

“…Similar mechanical performance was reported for other biobased aliphatic polyester cross-linked elastomers. For instance, photochemically cross-linked copolymer of α-methylene-γ-butyrolactone, ε-caprolactone and γ-butyrolactone of 95% gel content synthesized by Kang et al showed the tensile strength and elongation at break equal to 1.4 and 1.16 MPa, respectively . Decreasing the gel content to 92%, and thus the cross-linking density, however, resulted in not only a moderate decrease of Young’s modulus from 2.2 to 1.4 MPa, but also a dramatic increase, by approximately an order of magnitude, in tensile strength and elongation at break.…”

“…For instance, photochemically cross-linked copolymer of α-methylene-γ-butyrolactone, ε-caprolactone and γ-butyrolactone of 95% gel content synthesized by Kang et al showed the tensile strength and elongation at break equal to 1.4 and 1.16 MPa, respectively. 48 Decreasing the gel content to 92%, and thus the cross-linking density, however, resulted in not only a moderate decrease of Young's modulus from 2.2 to 1.4 MPa, but also a dramatic increase, by approximately an order of magnitude, in tensile strength and elongation at break. A copolymer of 1,4butanediol, 1,3-propanediol, sebacic acid, succinic acid, and itaconic acid radically cross-linked with dicumyl peroxide reported by Wei et al showed tensile strength and elongation at break of 0.79 and 0.64 MPa, respectively.…”

Direct Coupling of Biobased Bifunctional Hydroxy-Aldehyde Monomers to Chemically Recyclable Alipharomatic Polyesters via Dehydrogenative Polycondensation

“…Due to the significant increase in plastic production, leading to a depletion of fossil resources, there is an escalating urgency for the development of biobased polymers. − Among these polymers, biobased polyesters are considered indispensable and are typically synthesized through polycondensation of diacids with diols, hydroxy-acids, or ring-opening polymerization (ROP) of cyclic esters. Although incumbent commodity biobased polyesters such as polylactic acid (PLA), polyhydroxyalkanoates (PHAs), and polybutylene succinate (PBS) demonstrate favorable biocompatibility and degradability compared to traditional petroleum-based polyesters such as poly­(ethylene terephthalate) (PET) and poly­(butylene terephthalate) (PBT), further improvements are required in terms of strength, toughness, heat resistance, and barrier properties.…”

Transient Flexible Multimodal Sensors Based on Degradable Fibrous Nanocomposite Mats for Monitoring Strain, Temperature, and Humidity

“…The degradability occurs under alkaline aqueous conditions with a mass loss of 30% after 30 days. 29 In previous work, 30 citrate-based polyester elastomers (POC-PEGs) have been prepared and further functionalized with AgNWs. Flexible sensors assembled from POC-PEG−AgNWs composites exhibit excellent strain-sensing performances, and such sensors can be rapidly degraded.…”

“…For instance, mechanically robust, highly transparent, and degradable aliphatic polyester elastomers have been developed by ring-opening copolymerization (ROCP) and cross-linking. The degradability occurs under alkaline aqueous conditions with a mass loss of 30% after 30 days . In previous work, citrate-based polyester elastomers (POC-PEGs) have been prepared and further functionalized with AgNWs.…”