Experimental study on the thermal decomposition of two nitrocellulose mixtures in different forms

Abstract

In order to ensure the safety of nitrocellulose (NC) mixtures in storage, transportation and usage, it is necessary to study the thermal stability of NC mixtures. In the present study, the thermal decomposition of two commonly used nitrocellulose mixtures with different forms including soft fiber form and white chip form were investigated. Experimental results by differential scanning calorimeter (DSC) and simulation results by thermal safety software (TSS) were compared. The detailed structures of the two mixtures were also revealed by scanning electron microscope (SEM). It was found that the thermal properties such as onset decomposition temperature, maximum decomposition temperature, and temperature range of decomposition exhibit a difference between two forms of NC. Meanwhile, the effect of varying heating rates (5, 10, 15, and 20 °C/min) on thermal stability of NC with two forms was discussed. The results showed that the decomposition temperature increases with the increasing heat flow. Methods proposed by Ozawa and Kissinger presented a positive fitting result and similar calculated thermal kinetic parameters, indicating that the NC mixtures used in the present study follow a single-stage reaction. The simulation results also verified the applicability of the autocatalytic reaction for the two NC mixtures. The calculated activation energy of the simulation method is lower than that of the Ozawa and Kissinger methods. The results of all three methods show that the activation energy of NC-F is higher than NC-C.