Theoretical study on the mechanism of epoxy cured with tryptophan in the presence of 2,4,5-triphenylimidazole as a catalyst

► Epoxy cured with tryptophan in the presence of 2,4,5-triphenylimidazole. ► DFT study to investigate the mechanism of curing reaction at the level of BLYP/DNP. ► Approval of a four- step mechanism via atomic charges, MOs, and barrier energies.