Shelf Life Of Propellant Research Articles

Studies on the Effect of Ageing on Thermal, Ballistic and Mechanical Properties of Advanced Energetic Propellants

AbstractIn order to study the ageing behaviour of advanced energetic propellants during storage and the effect of nitrate ester on the shelf life, accelerated ageing tests were conducted on two types of propellants based on nitrate esters, BTTN (as P‐1) and NG:BTTN (1 : 1) mixture (as P‐2). Mechanical and ballistic characterization of P‐1 and P‐2 propellants were carried out during storage at ambient (27 °C) and elevated temperature (40 °C and 55 °C). During ageing, tensile strength and Young‘s modulus of propellants are increasing and percentage elongation is decreasing due to depletion of nitrate ester from the locus. Also, there is a loss of stabilizer with time during ageing. Thermal decompositions of P‐1 and P‐2 were studied using differential thermal analysis at four heating rates (1 °C/min, 2 °C/min, 5 °C/min, and 10 °C/min) during ambient and accelerated ageing. Activation energies for thermal decomposition were calculated using Kissinger's and Ozawa's methods by assuming first‐order reaction kinetics for first stage decomposition in DSC studies of aged propellants. The shelf life of propellants was predicted based on the classical Arrhenius equation using zero‐order kinetics of degradation of the propellant mechanical property i. e. percentage elongation. With the 30 percentage elongation as the critical evaluation parameter, predicted shelf life at 25 °C is 23.97 years and 12.17 years for P‐1 and P‐2 respectively.

Development of Nitrocellulose-based Propellants With Natural Stabilizers

Traditional stabilizers for nitrocellulose-based (NC-based) propellants are known to have carcinogenic, mutagenic and toxicity to reproduction potentials. Therefore, the replacement of these stabilizers in the propellants formulations is necessary, but with no losses regarding stabilization efficiency and shelf life of propellant. In this context, NC-based propellants were prepared using the natural substances curcumin and guaiacol as stabilizers. The chemical stability of the samples evaluated by a heat-flux microcalorimeter (HFC) suggests that the new propellants are more stable than the traditional ones. Also, a complementary in silico analysis was performed on toxicity prediction software (LAZAR, Toxtree, VEGA and TEST) based on the similarity with substances contained in their databases. The results concluded that curcumin stabilizer presents no toxicity, while guaiacol can have carcinogenic and mutagenic potential.