KuzkinaMat Posted December 16, 2011 Posted December 16, 2011 As an engineering challenge, I'm attempting to design a flash powder with a burn rate comparable to powdered aluminum/potassium chlorate/sulfur mixtures that does not require aluminum or other metallic dusts. This guy discusses KBrO3, Sulfur, and mannitol, but doesn't provide the proportions. My alternate proposal would be to replace mannitol with erythritol, a smaller molecule but with near identical structure, as well as replace the potassium bromate with potassium iodate. It is my thinking that the difference in activity between iodate and chlorate would obviate the sulfur incompatibility, though I don't know the properties of any iodine dioxide that might be present. Potassium permanganate (or even rubidium or cesium permanganate) might be even faster, but given its behavior towards glycerol, I don't trust it around erythritol.The slightest trace of moisture and it's gone. N.B. this is for demonstration purposes, rather than producing an actual service composition.
NightHawkInLight Posted December 16, 2011 Posted December 16, 2011 Whistle mix, or any number of chlorate comps are what you describe.
KuzkinaMat Posted December 16, 2011 Author Posted December 16, 2011 Whistle mix, or any number of chlorate comps are what you describe. I was under the impression that there were countless different kinds of whistle mix. Which ones see the most use?
NightHawkInLight Posted December 16, 2011 Posted December 16, 2011 I was under the impression that there were countless different kinds of whistle mix. Which ones see the most use? 70% Potassium perchlorate to 30% sodium salicylate or sodium benzoate are the most common whistle compositions. Sometimes a small percentage of red iron oxide is also added.
dagabu Posted December 16, 2011 Posted December 16, 2011 70% Potassium perchlorate to 30% sodium salicylate or sodium benzoate are the most common whistle compositions. Sometimes a small percentage of red iron oxide is also added. Then there is Patassium Benzoate and the addition of 1% Copper Oxychloride. That is my favorite since is isn't as hygroscopic as the sodium variety in my opinion (or did I get them switched again?). -dag
Potassiumchlorate Posted December 16, 2011 Posted December 16, 2011 Potassium benzoate is the less hygroscopic.
Ralph Posted December 16, 2011 Posted December 16, 2011 flash powder by definition is made with a metallic fuel. If you want a bright white light to accompany the report you may wish to use atleast some barium (either as part of the oxidiser or fuel) if you just want something with a really fast burn rate in open air like flash make some really fine grain bp from some high quality meal it is just as fast. TBH though this just looks like another thinly veild attempt at kewlish activities. Id recommend staying away from these kinds of comps whistle and flash are sensitive to shock ,friction and static.
optimus Posted December 16, 2011 Posted December 16, 2011 flash powder by definition is made with a metallic fuel. The ATF has a very loose definition: 55.11 Meaning of terms. Flash Powder. An explosive material intended to produce an audible report and a flash of light when ignited, which includes but is not limited to oxidizers such as potassium chlorate or potassium perchlorate, and fuels such as sulfur and aluminum.[1]
50AE Posted December 18, 2011 Posted December 18, 2011 If chlorates and sulfur are considered as dangerous, bromates and sulfur are even nastier and they are known to self ignite at nearly room temperatures! Just letting you know.
KuzkinaMat Posted December 18, 2011 Author Posted December 18, 2011 TBH though this just looks like another thinly veild attempt at kewlish activities. If I hadn't taken the time to browse the forums beforehand and read some of your other posts, I'd have considered this a personal jab and been offended, but I realize that given the subject matter such people must crop up with alarming regularity and your suspicion is understandable. So, to put this nonsense behind us politely, I am compelled to ask an honest question: How might I prove myself without being needlessly pedantic? P.S. I never do ground salutes.
KuzkinaMat Posted December 18, 2011 Author Posted December 18, 2011 If chlorates and sulfur are considered as dangerous, bromates and sulfur are even nastier and they are known to self ignite at nearly room temperatures! Just letting you know. Yes, the strange and peculiar nature of bromine has put me off of using its oxyanions in compositions. (Odd fact: while Br- can be oxidized to BrO3- with an ease relative to that for Cl- and ClO3-, oxidizing BrO3- to BrO4- is incredibly difficult for some reason science doesn't easily explain. IO3- oxidizes to IO4- without displaying this anomaly). Potassium Iodate, however, might well display different properties, since its reactivity with the oxidized sulfur would be different than for bromate; i.e. the displacement of S in SO2 with X to XO2 depends on the reactivity of the halogen X, which is much lower for iodine than bromine or chlorine. Iodine is closer to sulfur in electronegativity, making the redox less favorable. On the other hand, iodate is more sensitive than any of the others, as its hold on the oxygen is more tenuous due to its reduced electronegativity compared to other halogens. Whether this would result in spontaneous self-ignition with or without sulfur while in the presence of powdered erythritol is something I have yet to discover, but obviously will before working with any amount of the mix over half a gram. On a more practical note regarding iodine-based oxidizers: Electrolytically oxidizing such a large anion is giving me headaches. The solubility is so low, I'm getting barely 15 grams for a three day run, and I don't dare wash the KI off with alcohol given the oxidizing power of KIO3.
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