Magdy Bichay

AN INVESTIGATION OF SOME ALTERNATIVES TO LEAD BASED PRIMARY EXPLOSIVES

Beginning in 1993, a series of Executive Orders were issued that required the review and revision of all federal and military specifications and standards to eliminate or reduce procurement of extremely hazardous substances and chemicals by federal facilities. Accordingly, a program was established at NSWC-Indian Head to study the replacement of lead azides (LA) and normal lead styphnate (NLS) with materials not containing objectionable elements. One branch of this program consisted of the identification of existing compounds that could be exploited. The ten best potential alternates for lead azide and the ten best potential alternates for lead styphnate where identified. During this effort a number of the candidates were eliminated on grounds of synthesis impracticality and/or undesirable characteristics. RD-1333 and/or NLS were used as standards for all subsequent testing. A series of screening tests were performed to determine safety properties. A limited series of studies were conducted regarding solubility and chemical compatibility characteristics. Materials deemed suitable from the screening testing were then subjected to functional testing. One potential LA replacement and two potential NLS replacements have been identified.

Environmentally Acceptable Alternatives to Lead Azide and Lead Styphnate

A new material (copper(I) 5-nitrotetrazolate or DBX-1) has been prepared during the course of our investigations into possible replacements for lead azide. DBX-1 demonstrates a particle morphology that is well suited to handling and loading, has very low water solubility and has thermal stability and output characteristics that are equal to or greater than those of lead azide. Investigations into the suitability of DBX-1 as a lead azide replacement are ongoing. In addition, a lead styphnate replacement, KDNP (7-hydroxy-4,6dinitrobenzofuroxan, potassium salt) has completed initial screening tests at PSEMC and has been selected to undergo performance evaluation and compound qualification testing as outlined in NAVSEAINST 8020.5C. Synthesis, safety characteristics and output performance of these materials is described.

Improved Safety and Loadability of Coated DBX-1

ABSTRACT Several additives such as polyvinylpyrrolidone (PVP), polyvinyl butyral (PVB), and ethyl cellulose (EthocelTM) were selected to improve the flowability and safe pressing of copper(I) 5-nitrotetrazolate (DBX-1), a green replacement for lead azide currently under development. These properties are important for pressing the material into small-volume detonators, especially during manufacturing when saving cost, while maximizing efficiency and safety, is critical. Sensitivity tests such as ball drop impact, Bundesanstalt fur Materialprufung (BAM) friction, and electrostatic discharge (ESD) along with compatibility testing and performance testing in M55 stab detonators were conducted. For comparison, all testing was done on both uncoated DBX-1 (control sample) and DBX-1 coated with various additives. DBX-1 coated with PVP and PVB showed better flowability compared to the Ethocel additive. Moreover, a considerable safety improvement during pressing was observed with all coated DBX-1 samples compared to the uncoated control batch; whereas uncoated DBX-1 typically detonates when pressed to 35–40 kpsi, the coated DBX-1 could be pressed to greater than 70 kpsi with no adverse effect. More studies will need to be completed to find a suitable solvent for the safe long-term storage of DBX-1.