2026/07/01 by Elizabeth Alvarez Perez, Elizabeth Alvarez Pérez, Alice Mija
Engineering · Materials Science · #Epoxy Resin Curing Processes #Lignin and Wood Chemistry #Synthesis and properties of polymers
paper · pdf · doi:10.1016/j.eurpolymj.2026.114960
This study compares the structure–property relationships of fully bio-based polybenzoxazines derived from vanillin, daidzein, and naringenin using furfurylamine and ethanol under green synthetic conditions. The benzoxazine monomers were successfully synthesized and confirmed by FTIR and NMR spectroscopy, and their cured thermosets were evaluated by DSC, DMA, TGA, tensile testing, hardness measurements, and water absorption analysis. The results revealed a clear dependence of final properties on monomer functionality and backbone architecture. The daidzein-based polymer exhibited the highest glass transition and thermal resistance, whereas the naringenin-based thermoset showed the highest surface hardness and crosslink density with low water uptake. In contrast, the vanillin-based polybenzoxazine provided the best tensile performance and the highest room-temperature stiffness, although with slightly greater moisture absorption. The study demonstrates that bio-based benzoxazines can be tailored for distinct applications by selecting appropriate renewable phenolic precursors, with daidzein- and naringenin-based systems being especially promising for high-temperature coatings and adhesives, and vanillin-based materials for structural composite matrices.