The polymerization kinetics of potassium chloroacetate (MGL), potassium N-chloroacetyl-6-aminohexanoate (MEA), and their mixtures was studied by Fourier transform infrared spectroscopy. The bulk polycondensation reaction was faster for MEA than for MGL but kinetic differences in the selected temperature range (110130 degrees C) were not large enough to make unfeasible copolymerization of both monomers. A decrease in the activation energy was deduced for the polycondensation of monomer mixtures with respect to that determined for the homopolymerization reaction of the predominant neat monomer. differential scanning calorimetry data also showed significant differences in the exothermic polycondensation peaks that suggested an effective copolymerization reaction and favored the kinetic process over the corresponding homopolymerization. The resulting new poly(ester amide)s were characterized by spectroscopy and thermal analysis. 1H NMR spectra of samples with high MEA content revealed the existence of hetero-sequences whose ratio was slightly lower than that expected for a random polymerization of the two monomers. Samples with high molecular weights were only attained when the MGL molar ratio in the monomer mixture was lower than 65%. Calorimetric data showed that all samples were thermally stable and became amorphous for intermediate compositions. (c) 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012