Thermal degradations of used cotton fabrics and of cellulose: kinetic and heat transfer modeling

The thermal degradations of small samples of different used cotton fabrics and of cellulose, in comparison, in a thermogravimetric balance are considered under non-oxidative (100% N\(_{2}\)) or oxidative (20% O\(_{2}\), 80% N\(_{2}\)) atmospheres and for different temperature ramps (5–50 K min\(^{-1}\)). The associated kinetic parameters are determined for low temperature ramps using a differential isoconversional method or an Extended Independent Parallel Reaction model, with different reaction functions, and they are compared. Because these values of the kinetic parameters do not simulate in an appropriate way the thermal degradations of the materials at higher temperature ramps, a heat transfer model is proposed, which brings corrections to the temperature really acting inside the samples. With these corrections, the experimental and simulated mass loss rate curves do better superimpose, which leads to values of the kinetic parameters which are independent of the temperature ramp.