Chlorine-Free Red-Burning Pyrotechnics.

The development of a red, chlorine-free pyrotechnic illuminant of high luminosity and spectral purity was investigated. Red-light emission based solely on transient SrOH(g) has been achieved by using either 5-amino-1H-tetrazole or hexamine to deoxidize the combustion flame of a Mg/Sr(NO3 )2 /Epon-binder composition and reduce the amount of both condensed and gaseous SrO, which emits undesirable orange-red light. The new formulations were found to possess high thermal onset temperatures. Avoiding chlorine in these formulations eliminates the risk of the formation of PCBs, PCDDs, and PCDFs. This finding, hence, will have a great impact on both military pyrotechnics and commercial firework sectors.

High-performing red-light-emitting pyrotechnic illuminants through the use of perchlorate-free materials.

The development of perchlorate-free M662 40 mm illuminating pyrotechnic compositions is described. On the bases of cost, performance, and sensitivity, potassium periodate was determined to be most effective potassium perchlorate replacement in the compositions tested. The optimal periodate-based composition exceeded the performance of the perchlorate-containing control, exhibited low sensitivity values to impact, friction, and electrostatic discharge, and had high thermal onset temperatures.

High-nitrogen-based pyrotechnics: perchlorate-free red- and green-light illuminants based on 5-aminotetrazole.

Prototype testing of perchlorate-free hand-held signal illuminants for the US Army's M126 A1 red-star and M195 green-star parachute illuminants are described. Although previous perchlorate-free variants for these items have been developed based on high-nitrogen compounds that are not readily available, the new formulations consist of anhydrous 5-aminotetrazole as the suitable perchlorate replacement. Compared to the perchlorate-containing control, the disclosed illuminants exhibited excellent stabilities toward various ignition stimuli and had excellent pyrotechnic performance. The illuminants are important from both military and civil fireworks perspectives, as the perchlorate-free nature of the illuminants adequately address environmental concerns associated with perchlorate-containing red- and green-light-emitting illuminants.

Minimal fluorous tagging strategy that enables the synthesis of the complete stereoisomer library of SCH725674 macrolactones.

Four mixtures of four fluorous-tagged quasiisomers have been synthesized, demixed, and detagged to make all 16 stereoisomers of the macrocyclic lactone natural product Sch725674. A new bare-minimum tagging pattern needs only two tags--one fluorous and one nonfluorous--to encode four isomers. The structure of Sch725674 is assigned as (5R,6S,8R,14R,E)-5,6,8-trihydroxy-14-pentyloxacyclotetradec-3-en-2-one. Various comparisons of spectra of 32 lactones (16 with tags, 16 without) and 16 ester precursors (8 with tags, 8 without) provide insights into when and why related compounds have the same or different spectra.

Periodate salts as pyrotechnic oxidizers: development of barium- and perchlorate-free incendiary formulations.

In a flash: pyrotechnic incendiary formulations with good stabilities toward various ignition stimuli have been developed without the need for barium or perchlorate oxidizers. KIO(4) and NaIO(4) were introduced as pyrotechnic oxidizers and exhibited excellent pyrotechnic performance. The periodate salts may garner widespread use in military and civilian fireworks because of their low hygroscopicities and high chemical reactivities.

Recover, Recycle, and Reuse: Prove-Out of Pyrotechnic Illuminants Containing Demilitarized Magnesium.

The development and prove-out of yellow-light-emitting pyrotechnic illuminants based on recover, recycle, and reuse (R3 ) technology is described. Magnesium used in this investigation was recovered from four different illuminating pyrotechnic munitions by means of an environmentally friendly demilitarization process. Despite significant differences in the particle size and purity between the four lots of recovered magnesium, the performance of each lot-on evaluation in the M127A1 US Army yellow-light-emitting illuminant configuration-exceeded the military requirement and performance of the virgin magnesium-containing control. All formulations were found to have low sensitivities to various ignition stimuli and possessed high thermal onset temperatures. In addition to the military significance, this demonstrated "green" pyrotechnics technology of using recycled magnesium in illuminating pyrotechnics may also be of interest to the civilian fireworks community.