Eco-friendly eugenol curing agent-derived biobased epoxy resins for multi-functional integration

The investigation of bio-based epoxy resin has become increasingly significant, particularly for functional resins. However, research on bio-based resins that exhibit comprehensive performance advantages has seldom proceeded. To overcome this dilemma, the liquid amine curing agent AEESN was synthesized from bio-based eugenol and cysteamine, and then furnished the polymerization with three epoxy monomers, viz. DGEBA, TGAP, and TGDDM, respectively. The AEESN-based epoxy resin polymer, specifically DGEBA/AEESN, demonstrated an impact strength of 53.6 ± 7.78 kJ m −2 by a 1060 % increase, after storage at −20 °C, wherein less impact occurred on tensile and bending strength. Among them, the temperature control microphase separation process is responsible for such an impact enhancement. In addition, DGEBA/AEESN is also highly resistant to acidic and basic aqueous solutions. In contrast, the TGDDM/AEESN thermoset demonstrated good resistance to both organic solvents and aqueous solutions. Moreover, among different substrates, it was revealed that wood allowed the strongest adhesion for TGDDM/AEESN, reaching 4.14–7.48 MPa. Delightedly, all thermosets showed superior shape memory ranging from 100 °C to 150 °C and behaved with good sustainability, processability, and design freedom. Besides, superior optical shielding against UV and blue light may promote the use of functional coatings or lenses. Overall, the aforementioned bio-based AEESN epoxy resin exhibits good performance and outstanding functionality for applications.