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Accelerated Aging of a Composite Explosive
Author(s) -
Perrault G.,
Béadard M.,
Lavertu R. R.,
Tremblay M.
Publication year - 1979
Publication title -
propellants, explosives, pyrotechnics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.56
H-Index - 65
eISSN - 1521-4087
pISSN - 0721-3115
DOI - 10.1002/prep.19790040302
Subject(s) - explosive material , reaction rate constant , enthalpy , inverse gas chromatography , accelerated aging , composite number , analytical chemistry (journal) , chemistry , gas chromatography , kinetic energy , swelling , materials science , thermodynamics , composite material , chromatography , kinetics , organic chemistry , physics , quantum mechanics
A given formulation of a composite explosive was submitted to accelerated aging at 293 K, 333 K and 353 K for slightly over a year. Extensive determination of mechanical properties were conducted using an Instron Tester to characterize the aging process of the explosive as a whole. The change of elongation at maximum load can be fitted to a third‐order reaction rate giving an enthalpy of activation (Δ Ha) for the aging process of (78 ± 5) kJ/mol. Although the change of stress at maximum load was a function of temperature, it could not be predicted by a simple correlation. Swelling, inverse gas chromatography and N 2 O evolution by infrared were applied to the samples aged at 333 K. Swelling measurements show a regular increase with aging of the relative number of cross‐linking. Inverse gas chromatography at 373 K in helium indicated a first‐order kinetic aging process for every sample, but the rate constant (k) of the samples aged for 0, 30 and 60 days was slightly lower than the one for samples aged for 130, 250 and 375 days. The N 2 O evolution measured at 338.5 K in vacuum by infrared absorption indicates an aging process consisting of two consecutive first‐order reactions, the second one being ten times slower than the first one. The first stage, which was also studied by inverse gas chromatography, gives rate constants which are about half as large as those measured by chromatography and confirms the changes in behavior from the samples aged for 0, 30 and 60 days to the samples aged for 130, 250 and 375 days. These results are discussed in relation to an aging process by oxidative cross‐linking of the binder and degradation of the solid explosive.