Most of these have been synthesized and tested with respect to density, heat of formation, stability and sensitivity. Most of the energetic properties
are computed via semi-empirical methods such as the Kamlet-Jacobs equations. That is why I say that it remains to be seen whether these equations work
for this kind of material.
I believe that I can relatively easily prepare the material called ATRZ-1 ([Cu(4,4'-azo-1,2,4-triazole)3(NO3)2]n). It is basically made by mixing
boiling aqueous solutions of Cu(NO3)2 and 4,4'-azo-1,2,4-triazole, filtering and allowing the filtrate to slowly evaporate until crystals form. The
ligand 4,4'-azo-1,2,4-triazole is prepared by oxidative azo-coupling of 4-amino-1,2,4-triazole using sodium dichloroisocyanurate (pool chemical). As
mentioned previously, I possess 4-amino-1,2,4-triazole from an old experiment, and I have prepared 4,4'-azo-1,2,4-triazole (I hope). I will attempt
the synthesis of ATRZ-1, and also see what happens if Cu(ClO4)2 is substituted for the nitrate.
ATRZ-1 has a heat of detonation of more than 15 kJ/g, but a density of only 1.68 g/cc, so the performance is predicted to be only about the level of
HMX, but a perchlorate analogue might be better.
On another note, I received my carbohydrazide recently, and have prepared urazine following the procedure from Inorganic Synthesis vol 4. It involves
adding concentrated HCl and then slowly heating to 220C. Then water is added to dissolve the byproduct hydrazine*HCl, and the insoluble urazine is
filtered off. The yield exactly matched the litterature procedure. I then added a slight excess of sulfuric acid to the recovered filtrate, which
caused a large amount of white crystals to precipitate. This should be hydrazine sulfate, and after filtering, washing with cold water and drying, I
recovered a yield of about 70%. In total, 23.4 g carbohydrazide was converted to 11.5 g urazine and 15.6 g hydrazine sulfate.
The 1.16 g urazine was then reacted with one molar equivalent of 50% HClO4, and stirred for 1 hour at room temp, then 1 hour at 50C. Then the water
was evaporated by placing the entire mass in a petri dish and heating to 60C on the hotplate. The product UZP is very dense and extremely energetic
(in the hammer test), but moderately hygroscopic. I tried desensitizing it by dissolving 5 parts by weight of bees wax in a minimal amount of
detergent gasoline, mixing this with 95 parts of the UZP and evaporating the gasoline while continually agitating the mix. The sensitivity is indeed
reduced a little, but the wax does nothing for the hygroscopicity. The powder was pressed into a 7mm ID brass tube and easily achieved a packing
density of 2.05 g/cc, however, when this was tested in my usual setup, a very disappointing result of 2.92 mm dent depth in 20 mm Al bar stock was
achieved.
For comparison:
Picric acid: 3.53 mm
5-ATz*NO3: 3.84 mm
RDX: 4.13 mm
HMX: 4.35 mm
It was only at this point I discovered the hygroscopicity issue. I had left weighing boats with both some of the neat crystals and also some of the
wax treated powder in my workshop for testing. The relative humidity is slightly higher in my workshop than in my lab, and the samples that were in my
lab *looked* fine, but the ones in the workshop had visibly absorbed atmospheric moisture. It may certainly be possible to work around both the
sensitivity issue and the hygroscopicity (the right PBX formulation may solve both), but before working on that, I will conduct further tests to see
if better performance can't be achieved from the dry product. |
. Are there any denser more powerful ones you
can do… well if you decide to after reading dorniers post