Recyclable fully bio-based thermosets enabled by crosslinked naringenin-derived networks

The primary objective of this work was to create sustainable polyester flavonoid-based thermosets using triglycidyl ether of naringenin (TGEN), which exhibit high mechanical, thermal, and chemical performance while facilitating controlled chemical depolymerization and recycling. The reactivity of developed thermosetting bioresins was analyzed by in situ FTIR and DSC, showing enthalpy values ranging from 240 to 350 J/g and maximum reactivity between 138 °C and 150 °C, aligning well with industrial processing requirements. The thermomechanical performance, evaluated by DMA, was good with storage moduli ranging from 2.1 to 3.3 GPa in the glassy region, and damping factors spanning from 113 °C to 182 °C. Tensile tests analyses showed Young’s moduli values around 1.1 to 1.4 GPa while low brittleness values (0.04–0.072%·Pa/10 10 ) indicate their durability. The designed bioresins showed high thermal stability, with T 5% values > 308 °C and low values of water absorption ∼0.29% to 0.45%. The obtained thermosets were chemically disintegrated and introduced at 5‒10% in new formulations, giving improvements in stiffness (1.59 and 1.63 MPa) and storage modulus (3.44 and 3.72 GPa). Moreover, ten green metrics were evaluated to quantitatively assess the sustainability and greenness of the products.