Characterization of thermal decomposition mechanism and combustion performance of 4,4'-azobis(1,2,4-triazole)

4,4'-azobis(1,2,4-triazole) (ATRZ), as a representative of high-nitrogen compound, has attracted extensive interests. This work explores the thermal decomposition mechanism and combustion performance of ATRZ. The thermogravimetry-differential scanning calorimetry-fourier transform infrared spectroscopy (TG-DSC-FTIR) of ATRZ was carried out at heating rate of 10 degrees C/min in an argon atmosphere. ATRZ has two peak exothermic temperatures, 110.24 degrees C and 306.85 degrees C respectively. The exothermic peak at 110.24 degrees C is the decomposition of ATRZ tiny debris, and the exothermic peak at 306.85 degrees C is the decomposition of the main part of ATRZ. The pyrolysis-gas chromatography mass spectrometry (PY-GC/MS) of ATRZ was carried out at 350 degrees C in an argon atmosphere. By combining TG-DSC-FTIR and PY-GC/MS, the thermal decomposition mechanism of ATRZ was speculated. The main reaction in the ATRZ pyrolysis process is the cleavage of two N-N single bonds in the nitrogen bridge, forming a nitrogen molecule and two triazole rings, which is the majority of the first step decomposition reaction. At the same time, a small number of triazole rings break off to form other intermediates. A small amount of nitrogen gas is generated and a large number of CN clusters are formed. Under the same testing conditions, ATRZ has a higher combustion heat (19318 J/g) than other traditional CHNO energetic materials. By comparing the laser ignition combustion of ATRZ and ATRZ+RDX, the combustion temperature of ATRZ+RDX is higher and the combustion duration is longer. The introduction of CHNO type ammonium nitrate explosives promotes the energy release of ATRZ. All authors contributed to the study conception and design. Qi Pan and Xueyong Guo conceived and designed the above all experiments. Jianxin Nie prepared the experimental samples. Yanli Zhu and Shenghua Li conducted the experiments and analysed the results. The first draft of the manuscript was written by Qi Pan and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.**image