Effect of inorganic salt on the thermal degradation of nitrocellulose and reaction mechanism of its mixture

Abstract

In this study, to better understand the reaction mechanism between inorganic salts and nitrocellulose, CaCO3 and Li2CO3 were evaluated with respect to their effects on the thermal degradation of NC in nitrogen atmosphere using TG/DSC at three different heating rates (2, 5, 10 K/min). The numerical relationship between activation energy (E) and conversion rate was obtained by FWO and KAS method, and it was discovered that CaCO3 could improve the thermal stability of NC. Activation energy values were calculated by Kissinger method, and it was found that NC that contain Li2CO3 had the highest activation energy while NC containing CaCO3 had the lowest E value. By combining the thermal analysis data with Malek method, the most probable mechanism model of thermal degradation is obtained as Šesták-Berggren model, which expression is f(α) = αm (1 - α)n. As a result of this study, there are certain guiding principles that can be applied to the pyrolysis reaction model and to the actual production process of nitrocellulose.

Keywords

• Thermal analysis
• Thermal decomposition mechanism
• Malek method
• Nitrocellulose
• Inorganic salt