The use of the change of elongation for comparison of the shelf life of composite solid propellants in the air and nitrogen atmospheres

Abstract

This work uses the change of elongation with temperature in a composite solid propellant to assess its shelf life for the air and nitrogen atmospheres applying two methods for the temperature parameterization of the measured quantity, the Arrhenius and Berthelot equation. The samples of the composite propellant contain aluminum (Al), ammonium perchlorate (AP), and hydroxyl-terminated polybutadiene (HTPB) as well as curing agent toluene diisocyanate (TDI), which were aged at three temperatures 323.15, 333.15, and 343.15 K during 15, 30, 60, 90, and 120 days. Stress-strain curves for the samples are inves-tigated to study the effects of the atmospheres of air and nitrogen on the samples. The ratio of the changes in percentage elongation (ɛ) to the initial value of percentage elongation (ɛ r ) is the degradation criterion, which is defined as a reduction of the elongation to less than 50 %. The calculated activation energy by the Arrhenius method is 80.48 kJ mol À 1 for the air atmosphere. The shelf life of the samples were found to be 7.912 and 7.906 years (air atmosphere) to 23.38 and 23.36 years (nitrogen atmosphere) as well as Arrhenius and Berthelot methods, respectively.

Self-Assembly of Nitrogen-Rich Heterocyclic Compounds with Oxidants for the Development of High-Energy Materials

“…These structural characteristics could be employed to explain the good thermal stabilities of compounds 2 and 3 . Generally, the high decomposition activation energies ( E a ) of energetic materials indicate that the materials could have long shelf life . Herein, the E a of compounds 1–3 are measured by the Kissinger method based on the decomposition temperatures of these materials at different heating ratios of 10, 15, and 20 °C·min –1 (Figures S18–S20).…”

“…Generally, the high decomposition activation energies (E a ) of energetic materials indicate that the materials could have long shelf life. 44 Herein, the E a of compounds 1−3 are measured by the Kissinger method based on the decomposition temperatures of these materials at different heating ratios of 10, 15, and 20 °C•min −1 (Figures S18−S20). 45 The E a values for compounds 1−3 are 66.23, 29.7, and 34.58 kJ mol −1 , respectively, indicating that compound 1 could have the longest shelf time among the selfassembly materials.…”

Research on the Thermal Aging Performance of a GAP-Based Polyurethane Elastomer

“…Various properties of solid propellants (especially mechanical properties) are inevitably degraded during prolonged storage due to the influence of the environment and the interaction between the components [ 1 ]; this is known as aging [ 2 ]. During the aging process, solid propellants may suffer from deformation, cracking, and other damage [ 3 ], which gradually fail to meet the use requirements and give rise to serious safety hazards, so aging performance is crucial for propellants. Research on the aging mechanism of solid propellants can provide a basis for predicting service life, thus avoiding accidents caused by propellants not being scrapped in time at the end of their service life.…”