Aromatic amino acids as latent, bio-based curing agents and toughening agents for epoxy resins

In the realm of bio-based curing agents, recent investigations have focused on amino acids owing to their distinctive attributes. Nevertheless, the suitability of thermosets cured with aromatic amino acids as latent matrix materials for fiber-reinforced composites remains to be empirically established. Consequently, this study is oriented toward assessing the mechanical properties of diglycidyl ether of bisphenol A when cured with either L-tryptophan or L-tyrosine, in the presence of a latent, urea-based accelerator. The investigated properties include glass transition temperatures, tensile, flexural, compression, and fracture toughness properties. The predominant variations in the mechanical characteristics of these thermosets are confined to their Young's moduli and fracture toughness properties. This divergence is attributed to the greater presence of crystals in the L-tyrosine-cured thermoset, resulting in enhanced reinforcement and toughening effects compared to the L-tryptophan-cured thermoset. Influencing factors on the mechanical performance of amino acid-cured epoxides. image