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Laboratory of Liptakov
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Incredible exact description. Pity that final material is hygroscopic.....
Development of primarily - secondary substances CHP (2015) Lithex (2022) Brightelite (2023) Nitrocelite (2024)
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underground
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Quote: Originally posted by Microtek  | I gave NIHT a shot recently:
Hexamine (3.5 g, 25 mmol) was added to hydrochloric acid (37%, 10 ml) with stirring. When the hexamine was mostly dissolved, nitroguanidine (2.5 g, 24
mmol) was added in small portions over the course of 10 minutes. No exothermicity was seen.
The temperature was raised to 38 C, and kept at 38.0-38.5 C with stirring for three hours. When the temperature was raised, almost all of the solids
were dissolved, but after about 30 minutes, a white powdery precipitate was formed. The reaction was done in a fume hood as it evolves a lot of
formaldehyde.
After three hours, the mix was allowed to cool to 5 C, and was filtered, washed with ethanol on the filter, resuspended in ethanol, refiltered and
left to dry overnight. The collected product weighed 4.871 g, which is more than the used guanidine can account for. In an effort to purify the
product, it was added to 50 ml of distilled water and heated to dissolve it (the Metelkina paper does this). On cooling, small, white crystals
precipitated. These were collected by filtration, dried and weighed. Only 0.987 g had precipitated from the recrystallisation. In order to determine
the solubility of the isolated compound, an excess of the solid was added to distilled water, stirred for 5 minutes at 21 C and centrifuged. The
solution was then decanted into a pre-weighed petri dish, and the water was evaporated at 70 C. Re-weighing the petri dish showed 10 mg of solids had
been dissolved in the water, indicating a solubility of 1 g per liter of water at 21 C.
A second saturated solution was prepared and treated with AgNO3 soln, but gave no AgCl precipitate. This indicates that the product recovered from the
recrystallisation is not NIHT*HCl but probably the free base.
On the assumption that the solid was in fact NIHT free base, 0.15 g was mixed with an equivalent amount of HClO4, 50% and evaporated to dryness at 70
C. This gave a syrupy material that hardened to a candy like substance on cooling. It burns energetically and without smoke or residue, and is quite
sensitive to hammer blows. It is also quite hygroscopic, and absorbed enough moisture to turn liquid after 12 hours at 45% relative humidity and 21 C.
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Could you determine what the remaining 4g into the solution is ? Is there any possibility to be NIHT HCL and the rest 1g to be the NIHT freebase ?
Cause 1g of product seems a bit low.
[Edited on 21-1-2024 by underground]
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Microtek
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I'm sure that a lot of the crude material was in fact NIHT*HCl. I would say that NIHT is probably a very weak base, which coupled with the very low
solubility of the free base means that recrystallising it from water gives free NIHT. Aminonitroguanidine nitrate shows the same tendency. It migt be
better to recrystallise from hydrochloric acid. It's also possible that the crude material could be nitrated without purification but without
sophisticated analytical equipment, I think it is usually preferable to eliminate as many unknowns as possible.
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underground
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True. Will you continue more on this subject ? Let us updated pls.
Edit. Due to low solubility of NIHT freebase, adding NaOH to your crude product then recrystalize it out from water would yield NIHT freebase. I
wonder if NIHT HNO3 could exist. Dehydration /nitration of NIHT HNO3 with H2SO4 will yield NNHT which has similar or better performance than RDX
Edit2. Keep in mind that oxygen ruin the reaction for NIHT HCL production. It is better to seal the reaction beaker with a membrane or a balloon to
keep oxygen out.
[Edited on 22-1-2024 by underground]
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Microtek
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Precipitating the free base with NaOH might be a good idea, I'll try that at some point.
I did cover the beaker with a plastic film, so I don't think too much air would have gotten in (diffusion through tiny gaps is very slow without a
pressure differential). For my next run I can use a sealed apparatus to see if it makes a difference.
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