In this article, we report the degradation of poly(ethylene terephthalate) (PET), which occurs through glycolysis in the presence of dimethyl tin distanoxane [(CH3)(2)Sn(OCOCH3)(2)] as a catalyst, triethylene glycol (TEG) as a nucleophilic agent, and decaline like a solvent. A number of experiments were executed, which were derived from a factorial experimental design, in which the reaction time was between 40 and 60 min, the amount of TEG was between 3.4 and 5.6 g, and the amount of catalyst was between 0.04 and 0.06% in ratio to PET. The reaction temperature was constant at 175 degrees C in all of the experiments. Once the glycolytic depolymerization occurred, oligomers with a molecular weight around 6000 g/mol were obtained. These oligomers were analyzed through gel permeation chromatography, differential scanning calorimetry, Fourier transform infrared spectroscopy, and H-1-NMR. (c) 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3482-3488, 2013