Flash pyrolysis study of zinc carbohydrazide perchlorate using T-jump/FTIR spectroscopy

Carbohydrazide (CHZ, NH₂NHCONHNH₂) is a hydrazine derivative in white crystal form with strongly reducing behavior. Its coordination compounds can be used in different fields including medicine, petroleum, and energetic materials [1]. Carbohydrazide not only serves as an ingredient of propellants [2,3] but also can be combined into powerful explosives [4,5]. Recently, energetic carbohydrazide coordination compounds have received extensive attention due to their potential properties, such as good fluidity and suitable sensitivity [6-8]; in particular, the coordination compounds of carbohydrazide and perchlorate show good explosive properties. Preparation and characterization have been reported previously [9]. Kinetic parameters for the exothermic decomposition reaction are of great importance for understanding ignition, combustion, and explosion. However, relatively little is known about the chemistry at the surface during these processes, owing to many parallel multiphase reactions over a short linear dimension caused by the steep temperature gradient. T-jump/FTIR spectroscopy [10] can be used as an effective method for studying flash pyrolysis of energetic materials. The concentration of the gas products can be resolved as a function of temperature and pressure [11-13]. The global kinetic parameters of the exothermic decomposition reaction can also be determined by the time-to-exotherm ( t_x ) values derived from control voltage traces of the Pt filament [14-16]. The aim of this work is to identify gas products and explore the global kinetics of the exothermic decomposition reaction of the title compound. These data are quite useful in the evaluation of thermal stability under rapid heating conditions and can be incorporated into steady combustion modeling.