The H-mordenite zeolite catalyzes the polymerization of N,N-diethanol acrylamide (DEAA) with phthalic anhydride (PA) yielding polyesteramide (PEA) resin. The Fe modified mordenites showed lower activity than that of H-mordenite that presented high stability on multiple recycling. The formation of DEAA; the principal step in forming PEA, was occurred through the condensation reaction of diethanol amine (DEA) and acrylic acid (AA) with 91% selectivity in addition to 9% devoted for the corresponding ester (diethanol amine monoacrylate; DEMA). The IR spectroscopic study of DEAA formation in the presence of mordenite zeolite reveals the greater affinity of the reactants specifically AA to protons that are likely to be the initiators of the DEAA formation. The formation of ester was confirmed through the appearance of a band at 1735 cm(-1) attributed to the stretching vibration of C=O of ester groups. A possible reaction mechanism is proposed based on data reported in the literature and the results of the present investigation. The activation energy of the DEAA formation was found to be 35.5 kJ mol(-1), for non-catalyzed and 11.46 kJ mol(-1), for the H-mordenite catalyzed one. The acidic and textural properties of the catalytic samples have been measured using NH3 adsorption (at 150degreesC) and N-2 adsorption (at -196degreesC), respectively. The results obtained indicate the importance of the zeolite acid selectivity towards amide and ester formation. (C) 2003 Elsevier B.V. All rights reserved.