High-performing biobased epoxy resins from resveratrol and HMF via a dual-curing process

Since little attention has been paid to the dual biobased epoxy resin monomers, a novel monomer (ResCMF) from resveratrol and 5-hydroxymethylfurfural was designed for the biobased network fabrication with diaminodiphenyl disulphide (AFD) as a hardener. Comprehensive behaviors of the solvent-free cured networks were investigated. In contrast to the epoxide-amine polymerization in DGEBA/AFD, an additional amine-catalyzed self-polycondensation of ResCMF also occurred during ResCMF/AFD formation. According to the activation energy estimation of the epoxide-amine reaction, the 44AFD hardener is more reactive than the 22AFD. For ResCMF/AFD, the initial epoxide-amine polymerization allowed the network with a moderate T g of about 107.2/109.3 °C, while the self-polycondensation showed high T g values at 194.6 /188.6 °C. Moreover, ResCMF/22AFD outperformed ResCMF/44AFD in terms of storage modulus (4.55 > 3.21 GPa), larger than that of the DGEBA/AFD. It demonstrated outstanding tensile strength (85.1 ± 3.5 MPa) and high flexural strength (118.4 ± 18.9 MPa) as well. Meanwhile, comparable impact and lap shear strengths were observed for all networks. Interestingly, high-performance shape-memory ResCMF/AFD at 150 °C enabled the sustainable reprocessing. Furthermore, in general, the thermosets showed good solvent resistance. Nonetheless, the sustainable post-treatment via DMF-induced solvolysis enables ResCMF/AFD degradation. As a result, the dual-cured ResCMF/AFD networks provide good overall performance for their applications in the future.