Thermogravimetric analysis during the decomposition of cotton fabrics in an inert and air environment

The thermal degradation of samples of used cotton fabrics has been investigated using thermogravimetric analysis (TGA) between room temperature and 700 °C. Experiments were carried out with about 5 mg of sample in three different atmospheres: helium, 20% oxygen in helium and 10% oxygen in helium. Three different heating rates were used at each atmosphere condition. A kinetic model for the decomposition of used cotton fabrics explaining the behavior of all the runs performed has been proposed and tested. For the pyrolysis of the cotton, the model comprises two parallel reactions. For the combustion process, one competitive reaction was added to each parallel reaction of the pyrolysis model and four combustion reactions of the different solid fractions to obtain volatiles. One single set of parameters can explain all the experiments (pyrolysis, oxidative pyrolysis and combustion) at the three different heating rates used.