TGA-FTIR study of the pyrolysis of sodium citrate and its effect on the pyrolysis of tobacco and tobacco/SBA-15 mixtures under N 2 and air atmospheres.

In this work, the effect of sodium citrate mixed with tobacco, in the presence and absence of SBA-15 material, was studied by thermogravimetric analysis coupled to Fourier-transform infrared spectrometry under N2 and air atmospheres. Depending on the atmosphere used, the decomposition of sodium citrate changes considerably at high temperatures, mainly due to the oxidation of the residue. The analysis of the experimental and calculated derivative thermogravimetric data of the sodium citrate/SBA-15 mixtures allows the observation of marked widening of the peaks appearing at lower temperatures, due to the presence of SBA-15, while the expected peak at high temperatures in air completely disappears. The presence of sodium citrate in tobacco and tobacco/SBA-15 mixtures produces changes, especially in air atmosphere, where the main peaks increase their intensity, whereas decreasing that of the oxidation of the residue at around 450 °C and an important peak appears at 630 °C. In N2 atmosphere, all decomposition processes of tobacco proceed at lower temperatures and with higher intensities. The peak due to the citrate at temperatures around 200 °C completely disappears in all samples. © 2018 Society of Chemical Industry.