Experimental insight into interaction mechanism of 1H-tetrazole and nitrocellulose by kinetics methods and TG-DSC-FTIR analysis

Abstract

Nitrogen heterocycles as Nitrogen-rich energetic material has been widely popularized due to their desirable properties like low sensitivities, excellent stability, and lower environmental impact, less erosive and less toxic combustion gases, especially in gun propellant application areas. The focus of this study is on investigating interaction mechanism of 1 H-tetrazole (1 H-TZ) and nitrocellulose (NC) by kinetics methods and TG-DSC-FTIR analysis. The mixture (NC-TZ) between 1 H-TZ and NC was prepared by means of physical blending. DSC experiments indicated that the open and closed environment can generate different and important influence on the chemical reaction between 1 H-TZ and NC. Combined with the change of activation energy, it illustrated that the gas 2 H-tetrazole, the isomer of 1 H-TZ, had a significant influence on the thermal decomposition of NC. In comparison with kinetic models of NC and NC-TZ, it can be found that the addition of 1 H-TZ mainly affected the contribution factor and m value in the first stage. The value of m decreased from 1.00 to 0.15, meanwhile, the contribution factor was decreased from 0.50 to 0.12. It showed that NO2, the initial decomposition product of NC, had taken part in the thermal decomposition process of 1 H-TZ. TG-DSC-FTIR experiments indicated that there was a chemical reaction between 2 H-tetrazole and the initial decomposition product of NC, NO2, to form CO, N2O and HN3.