Polypyrrole material for the electrostatic discharge sensitivity mitigation of Al/SnO₂ energetic composites

Abstract

Nanothermites are composite energetic materials made of fuel and oxidizer nanoparticles characterized by impressive exothermic reactions (highly flame temperatures and impressive heat combustion releases). However, nanothermites suffer from their high electrostatic discharge (ESD) sensitivity that may be at the origin of accidental ignitions during handling. The present study deals with the use of doped-polypyrrole conducting polymer in aluminum/tin (IV) oxide energetic formulation (Al/SnO 2 ). X-ray diffraction, Fourier transforms infrared spectroscopy, scanning electron microscopy, conductivity measurements, sensitivities and combustion tests were implemented to characterize the polypyrrole-doped Al/SnO 2 energetic composite. The results revealed a significant gradual ESD desensitization of the nanothermite (<0.14 mJ to 246.40 mJ) as a function of the doped-polypyrrole amount (0 to 15 wt%). The reactive properties of the polypyrrole-enriched Al/SnO 2 nanothermite were verified and an acceptable reactive behavior was claimed. The successful adding of doped-polypyrrole conducting polymer within energetic nanocomposites is reported for the first time.

Spark Desensitization of Nanothermites via the Addition of Highly Electro-Conductive Carbon Particles

“…In ESD sensitivity testing, bulk powders are examined (TMD < 10%) and therefore the contact area between the particles is not as high and the conductivity properties may be lower. This result is not entirely consistent with previous works dedicated to the spark-desensitization of nanothermites by means of conductive component additives [10,12]. When conductive polymers (polyaniline, polypyrrole) are used, the curves are superimposed.…”

“…For this purpose, a BFH-12 drop hammer device, a FSKM-10 friction device, and a 2008 ESD tester, all from OZM Research, were used. A description of each tool and the measurement principles has been given in other papers [9,10,12]. Regarding the combustion events (ignition and burning) of Al/WO 3 nanothermites w/o high-conductivity carbon nanoparticles, the tests were performed (under a fume hood) using an optical flash device described in [10].…”

“…A description of each tool and the measurement principles has been given in other papers [9,10,12]. Regarding the combustion events (ignition and burning) of Al/WO 3 nanothermites w/o high-conductivity carbon nanoparticles, the tests were performed (under a fume hood) using an optical flash device described in [10]. Typically, 10 ± 1 mg of energetic nanocomposite was placed on a glass substrate (50 mm 2 surface area) held at a distance of 1 mm above the optical igniter (energy of 0.11 J/cm 2 ).…”

“…The additive should be inert to the thermite reaction and its concentration in the energetic material should be as low as possible, so that the overall pyrotechnic performance is not significantly changed. Among the conductive additives investigated-carbon, conductive polymers, and metals [4][5][6][7][8][9][10][11][12][13][14]-carbon structures such as nanotubes, graphene, graphite, and carbon black are efficient alternatives. For example, the Al/CuO energetic nanosystem could be desensitized to spark with an addition of 13 vol.…”

Al/SnO2 Nanothermite ESD Desensitization by Means of the Elaboration of Tailored SnO2–Polypyrrole Composites

“…This study focuses on an investigation of the polypyrrole (PPy) conducting polymer and specifically on its microstructure in a SnO 2 –PPy composite. The polymer has already been used as a desensitizer thanks to a ternary addition within the energetic medium and showed promising results for ESD desensitization . The Al/SnO 2 composition, chosen for this work, is extremely sensitive to the ESD stimulus with a threshold of below 0.14 mJ (device limits).…”