Kinetic Model of Stabilizer Consumption and Shelf-Life Prediction of Single-Base Propellants

Accurately predicting the shelf-life of single-base propellants loaded in ammunition is crucial for ensuring its safe storage and use. In this study, based on the results of the aging experiments, the reduced time graph method was used to infer the most probable integral mechanism function G(α) = 1 − (1 − α)^1/2 (degree of agreement R² = 0.9730), for the DPA consumption reaction, which proceeds via a phase-boundary reaction. Then, based on the research results of G(α), with a 50% decrease in the DPA as the failure criterion, the Arrhenius and Berthelot equations were used to establish DPA consumption kinetic models, respectively. The shelf-life prediction equations for single-base propellant were obtained as τ = 6.66 × 10⁻¹⁷exp(14 342.78/T) and τ = 10^{(18.67 − 0.0489T)}. Finally, the shelf-life predicted by the Arrhenius and Berthelot methods was compared at storage temperatures in the range of 293–338 K. The shelf-life of single-base propellant predicted by the Berthelot method was much shorter than that of the Arrhenius method at storage temperatures in the range of 293–308 K. The Arrhenius method showed a greater dependence on the storage temperature T and DPA reaction rate constant k than the Berthelot method, while the Berthelot method was more dependent on the multiple increase of the k (3.08 times for a 10°C increase in storage temperature). This study provides both theoretical and experimental data support for the accurate prediction of the shelf-life of single-base propellants in ammunition, as well as a reference for the shelf-life prediction of nitrocellulose-base solid propellants.