Study on the influence mechanism of lead carbonate salt compounds on the combustion behaviors of 5AT/Sr(NO3)2 solid propellant

5-Aminotetrazole (5AT)/strontium nitrate (Sr(NO 3 ) 2 ), as a novel energetic material and low-emission nitrogen-rich fuel, has been extensively applied to the formulations of solid propellant gas generators (SPGGs) fire extinguishing technology due to its advantageous physicochemical characteristics. However, the shortcomings of high combustion temperature and low burning rate of this energetic material formulation of 5AT/Sr(NO 3 ) 2 restrict its further application and development in SPGGs fire extinguishing technology. To address these existing problems and enhance its combustion behaviors, lead carbonate salts (lead carbonate or basic lead carbonate) are incorporated as combustion modifiers in this study, and systematically investigates the effects of these two modifiers on its thermal decomposition and combustion behaviors. The results show that after adding them, the samples all exhibit three pyrolysis stages. Since the additives exhibit incomplete thermal decomposition during the initial stage, they show little catalytic effect on the first pyrolysis stage, and the catalytic effects are mainly reflected in the latter two stages. In addition, both additives show good cooling effects, significantly reducing the combustion temperature of propellant. The maximum burning rate of the samples with additives is higher than that of 5AT/Sr(NO 3 ) 2 , and the samples with 2PbCO 3 •Pb(OH) 2 demonstrates the superior burn rate over the samples with PbCO 3 . The findings establish both mechanistic understanding and practical guidelines for optimizing 5AT/Sr(NO 3 ) 2 propellant formulations in SPGG fire suppression systems.