Studies on diaminoglyoxime (DAG): Thermolysis and evaluation as ballistic modifier in double base propellant

Abstract

This paper reports thermolysis of diaminoglyoxime (DAG) and its evaluation as a ballistic modifier in double base propellant formulations. Differential scanning calorimetry (DSC) and simultaneous thermal analysis (DTA–thermogravimetric (TG)) revealed that DAG decomposes in two stages. Kinetics of initial stage of thermal decomposition of DAG evaluated from TG data gave activation energy ( E a) of 153 kJ mol −1. The high-temperature Fourier transform Infrared (FTIR) spectra of DAG suggested preferential cleavage of N O and C NH 2 during decomposition. Mass spectral data also suggest possibility of similar process. The hyphenated TG–FTIR data also revealed the evolution of gases containing species, such as CN, NH, OH and oxides of nitrogen during thermal decomposition. Evaluation of DAG as a ballistic modifier in RDX incorporated double base propellant formulations indicated that it brings down the pressure index to 0.17 compared to 0.79 for a control composition in the pressure range 6.9–8.8 MPa when used in combination with basic lead salycilate (BLS). The study suggests that combination of DAG and BLS need to be optimized to achieve more remarkable effects than BLS alone. It was observed that DAG does not have adverse effect on vulnerability and chemical stability of the propellant formulation.