Ignition experiments and models of a plastic bonded explosive (PBX 9502)

Abstract

Ignition experiments from various sources, including our own laboratory, have been used to develop a simple four-step, pressure-dependent ignition model for PBX 9502, which is composed of 95% by mass triaminotrinitrobenzene (TATB) and a 5% by mass chlorotrifluoroethylene/vinylidine fluoride binder. The four-steps include drying, mono-furazan formation, and decomposition of mono-furazan and TATB into equilibrium products. Our experiments were both sealed and vented and included various ullage percentages ranging from 18% to 75% of unfilled confinement volume. Our sample densities ranged from 38% of the theoretical maximum density (TMD) to 98% TMD. We observed a decrease in ignition times with the higher density samples, an increase in ignition times with increased venting, and an increase in ignition times with increased ullage. From our experiments, we conclude that decomposition of PBX 9502 is pressure dependent, open pore decomposition occurs in low-density experiments, and that closed pore decomposition occurs when the samples are pressed to near full density. In some of our confined high-density experiments we have observed for the first time, multiple temperature excursions prior to ignition caused by internal pressure generation.

TATB Sensitivity to Shocks from Electrical Arcs

“…As a worst-case, an electrical arc is assumed to penetrate through the explosive with a cylindrical symmetry around the arc. Carbon is a major TATB reaction product [12]. A preceding lightning stroke could leave a carbon track at a considerably higher temperature; if a succeeding stroke follows the track, it would start the arc.…”

Effects of Fluoropolymer Binders on the Mechanical Properties of TATB‐Based PBX

“…PBX which refer to a particle filled composite consisting of 90 %-95 % weight of powerful explosive crystals held together by a certain amount of polymeric binder, are being extensively used in energetic field [7][8][9][10][11][12]. Although the content of binder in PBX is relatively small (normally 5-10 %), it has significant influence on the thermal, mechanical, safety and detonation properties of explosives, in which the mechanical properties of explosives are particularly dominated by the binder [13][14][15][16][17].…”

Effect of Crystal Quality and Particle Size of HMX on the Creep Resistance for TATB/HMX Composites

“…On the other hand, TATB has attracted intense interest in the past decade, due to the moderate energy output combined with good heat resistance [10][11][12][13][14]. Polymer bonded explosives (PBXs) based on TATB, such as LX-17 (92.5 % TATB and 7.5 % kel-F800 by weight) and PBX-9502 (95 % TATB and 5 % kel-F800 by weight) have been developed in the last decades [15][16][17].…”