A mixture of bis(tetrazole)methane and ammonium dinitramide as a gas generator: synthesis, characterization, thermal behavior and kinetic study

Abstract

Bis(tetrazole)methane (H₂BTM), an eco-friendly nitrogen-rich compound, is insensitive to impact, friction, and static electricity, making it suitable for use as a solid fuel in gas-generating compositions for automotive airbag systems. In this study, firstly a novel complex, diammine-(5,5'-methylenebis(tetrazolato))zinc(II), Zn(BTM)(NH₃)₂, was synthesized and characterized; subsequently, H₂BTM via a one-pot process was obtained from synthesized complex as a novel precursor. Finally, the thermal behavior of mixture containing H₂BTM as a solid fuel and ammonium dinitramide (ADN) was investigated. For the characterization of the investigated compounds, PXRD, DSC/TGA, bomb calorimetry, ICP‒AES, CHN and FT-IR techniques were employed. The combustion reaction between the fuel and the oxidizer is a relatively complete reaction, accompanied by approximately 95% mass loss of the total mixture due to gas generation. The Kissinger–Akahira–Sunose (KAS) and Ozawa–Flynn–Wall (OFW) methods indicate an increase of 28.8 kJ mol⁻¹ in the activation energy of the mixture compared to pure ammonium dinitramide (ADN). Meanwhile, the decomposition reaction rate of the mixture is 2.6 times higher than that of either the pure fuel or the pure oxidizer. These results confirm that H₂BTM can be considered as new component in the chemical gas generating system.