Shelf Life Prediction of Picric Acid via Model-Based Kinetic Analysis of Its Thermal Decomposition

Abstract

A priori knowledge of the shelf life of energetic materials (EMs) is relevant due to its direct association with safety and functionality. This paper proposes a quick and reliable approach to predicting the shelf life of EMs whose thermal decomposition is an autocatalytic process once their failure threshold has been defined as a function of the limiting extent of conversion. This approach is based on the assumption of a kinetic law consistent with the autocatalytic behavior and on the subsequent extraction, via a suitable procedure of parameter identification, of the kinetics of thermal decomposition from differential scanning calorimetry (DSC) data gathered under dynamic conditions at three different heating rates. Its reliability is proven for picric acid (PA) through the comparison of kinetic predictions with evaluations of conversion obtained by using high performance liquid chromatography (HPLC) analysis for samples subjected to isothermal and non-isothermal accelerated aging tests, as well as for a sample of naturally aged material, i.e., PA, stored at room temperature for more than 10 years.

An Alternative Approach for Predicting the Shelf Life of Energetic Materials

“…Evidence and examples to support the perspective outlined in this work come from few literature studies [8][9][10][11]. In such studies, both isoconversional [8,9] and model-based [10,11] methods were adopted to determine the decomposition kinetics of energetic materials (EMs) from the data of thermal analysis experiments performed under dynamic conditions at different heating rates. In the latter methods, the kinetic law is predetermined based on the thermal behavior of the substance under examination.…”

“…In Refs. [8][9][10][11], kinetic predictions were compared with experimental data obtained on actual aged samples. Table 2 provides a global overview of these literature works in terms of investigated EMs, adopted kinetic approach, calculated kinetic predictions, and aging tests carried out for validating the kinetics at lower temperatures.…”

“…Global overview of Refs. [8][9][10][11] in terms of investigated EMs, adopted kinetic approach, calculated kinetic predictions, and aging tests performed for validation. In the last column, remarks on the agreement between kinetic predictions and experimental aging data are also reported.…”

“…An extensive validation of kinetic predictions against experimental aging data was carried out in Ref. [11]. Specifically, attention was focused on picric acid (PA), an explosive belonging to the class of aromatic nitro compounds (like trinitrotoluene (TNT)).…”

Effect of Stirring Speed and Stirring Time on Characterization of Clindamycin HCL Ethosomal and Ich Q1a (R2) Stability Test

“…The Arrhenius equation is used to obtain K and Ea values which describe the velocity of vesicle decomposition and the minimum energy of chemical reactions. Besides that, it can also be used to calculate the shelf life of a drug with a formula according to the release kinetics model [20,21].…”