Study of the influence of NaOH treatment on the pyrolysis of different leather tanned using thermogravimetric analysis and Py/GC–MS system

This paper presents a study of the influence of a NaOH treatment on leather samples tanned using different tanning agents. Thermogravimetric analysis (TG/DTG) and flash pyrolysis (Py/GC–MS) was carried out on treated samples, and the results were compared with those obtained with the untreated samples. Treatment with sodium hydroxide seemed to decrease the temperature of maximum leather decomposition rate between 4 and 27 °C, depending on the tanning agent, and increased the range of temperatures where leather degradation occurs. From flash pyrolysis experiments, it was found that the volatile products obtained from NaOH-treated samples contain higher amounts of nitrogen compounds than those obtained from untreated samples. The results of a multivariate analysis applied to pyrolytic products obtained in the flash pyrolysis of samples showed greater similarity between the results obtained in all treated samples than between treated and untreated samples produced with the same tanning process.