Effects of nitrogen content on pyrolysis behavior of nitrocellulose

Abstract

Although the thermal decomposition of nitrocellulose (NC) has been comprehensively examined, the effects of nitrogen content on the pyrolysis behavior of NC have not been clearly elucidated. In this work, the macro- and microstructures of NC samples with varying nitrogen contents were qualitatively and quantitatively analyzed. Higher nitrogen contents in NC samples were found to be associated with an increased number of nitro groups and cracks in the fiber surface. To elucidate the NC pyrolysis process and provide a theoretical basis for enhancing its stability, the pyrolytic behavior of NC was examined using thermogravimetric analysis-Fourier transform infrared spectrometry and pyrolysis-gas chromatography-mass spectrometry. The pyrolysis of NC primarily occurred within a temperature range of 180–240 °C; however, the peak temperature of the mass loss rate decreased with increasing nitrogen content. The initial nitrogen oxide produced by pyrolysis was nitrogen dioxide (NO2). During the main stage of pyrolysis, a wider variety of gases was produced by NC having a higher nitrogen content, with more cyclization recombination forms occurring in the post-reaction stage of pyrolysis. Based on the findings of this study, a detailed process of NC pyrolysis has been proposed.