Sustainable, Naringenin-Based Thermosets Show Reversible Macroscopic Shape Changes and Enable Modular Recycling

A sustainable biobased thermoset exhibiting shape-memory behavior and modular recycling capabilities has been developed herein. The prepared thermoset consists of naringenin and biocompatible polymer components. Naringenin, which has three phenolic moieties, has been converted to a multifunctional monomer containing glycidyl groups and readily formed a thermosetting network via epoxide ring opening reaction with a poly(ethylene glycol) diacid under solvent-free conditions. The resulting material is malleable yet as strong as articular cartilage and selectively absorbs water when compared with n-dodecane oil. Moreover, the thermoset can be physically reused. After being crumpled, stretched, or coiled, the initial shape of the material is restored in response to heat or water. Furthermore, the material is amenable to chemical recycling in a bulk state via transesterification, and its components can be recovered on a molecular level after degradation under benign conditions, as was confirmed using a model compound.