AbstractNew diglycidyl esters coming from the corresponding diacids and epichlorohydrin were synthetized using a quaternary ammonium salt as a catalyst. The new asymmetric compounds were characterized by spectroscopic methods and employed as starting monomers in a crosslinking process. The course of the reactions was followed by IR spectroscopy. Some intermediate species were identified in the onset of the reactions by recording13C‐NMR spectra until the products became insoluble in the usual deuterated solvents. The thermal behaviour of these cured epoxy resins was also studie