Eugenol as a Renewable Platform for Polyfunctional Co‐Hardeners for Tunable Epoxy Resins: From Synthesis to Multiscale Functional Characterization

Partially bio‐based epoxy thermosets were developed using diglycidyl ether of bisphenol A (DGEBA) and two biobased amines hardeners. A novel tetra‐functional amine was synthesized from eugenol via oxidative coupling to form di‐eugenol, followed by thiol‐ene functionalization. Five formulations were prepared by varying the molar ratio of the two biobased amine hardeners to tailor the network architecture. Thermomechanical properties were evaluated by differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). Furthermore, Solid‐State 1 H NMR provided a multiscale experimental approach into the relationship between cross‐link density, molecular chain dynamics, and macroscopic thermomechanical properties, leading to a straightforward structure‐property correlation.