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Author: Subject: Xylitol Pentanitrate (question)?
quicksilver
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[*] posted on 7-11-2009 at 15:43


PATENTS:
us1850225 Inositol hexanitrate
us1951595 initiation application / related material for Inositol hexanitrate

us2204059 recrystallization methodology; excellent long term storage & pre-neutralize crystal formation info

us2370437 urea used for favorable equilibrium shift (solid alcohol nitration) - works great for tough ones like sorbital that alters into liquid state during nitration, etc.

Older patents will often have less "manufacturing secrets" than material from the 1950's +
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hissingnoise
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[*] posted on 8-11-2009 at 06:06


Those compounds seem of little interest to the HE hobbyist; the positive OB makes the first more oxidiser that useful HE and sorbitol hexanitrate, though somewhat less oxygen-rich is MHN in a difficult liquid form. . .
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[*] posted on 9-11-2009 at 19:58


"Slight excess volume" sounds like you need more that one equivalent. Try "catalytic amount." Usually a fraction of a percent. I've found that the acidic (HNO3) nitration of sucrose runs away with as little as 2% equivalent H2SO4. I fogged out a lab with NO2 trying to make nitrosucrose, so I know first hand. I'd start with about 1% equivalent and work up or down from there.

Work out a reaction diagram and calculate your theoretical conversions from reactants to products. If you want ALL of your alcohols to nitrate, then you'll need (in the case of XPN) 5 molar units of nitrate to 1 unit of xylitol. If your calculations come out correctly, for every 1g xylitol, you'll need about 3.32g potassium nitrate and 6.2mg of 96% sulfuric. Keep the reaction in an ice bath as a minimum, and use as little water as possible. (50 ml?)

As for MHN and SHN being more or less oxygen rich than one another? Not a chance. The only difference between sorbitol and mannitol is their absolute configurations, or the way their chiral centers are oriented. As far as quantitative conversion of the alcohol to the nitrate, they are identical, as their molecular formulas are identical. They're just enantiomers of one another.

[Edited on 11-10-2009 by LabRatNW]
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[*] posted on 10-11-2009 at 13:31


Quote:
"Slight excess volume" sounds like you need more that one equivalent. Try "catalytic amount." Usually a fraction of a percent. I've found that the acidic (HNO3) nitration of sucrose runs away with as little as 2% equivalent H2SO4. I fogged out a lab with NO2 trying to make nitrosucrose, so I know first hand. I'd start with about 1% equivalent and work up or down from there.


Forget the idea of making nitric esters of aldehydes (sucrose is a aldehyde) as a beginner. They will oxidize. Ever done the the silver mirror experiment?

The H2SO4 is only one reason for it, as it dehydrates the sugar. The big problem is the trace amount of NO2 in your nitric acid. And as soon as something is oxidized, more NO2 is produced =>runaway.
And aldehydes are easily oxidized as said before.

[Edited on 10-11-2009 by hinz]
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hissingnoise
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[*] posted on 11-11-2009 at 02:50


Quote: Originally posted by hinz  

Forget the idea of making nitric esters of aldehydes (sucrose is a aldehyde) as a beginner. They will oxidize.

The aldehyde group in sucrose doesn't interfere with nitration by mixed acid provided the temp. is low enough, i.e. ~ 0*C. . .
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LabRatNW
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[*] posted on 23-11-2009 at 21:05
Question about nitrating poly-alcohols


Does KNO3 work okay? I know most people recommend NH4NO3, but I already have the potassium salt.
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[*] posted on 24-11-2009 at 03:20


Does KNO3 work for what?
(be more clear in your questions)

This nitration takes something a little more than just SA/XNO3.
These mixtures tend to get very thick thus having a very bad heat transfer, and a sugar so easy oxidized/attacked does not like that.
A runaway is prone to happen if you use KNO3.
NH4NO3/SA is more stir able but still has this issue.


Something that could work is adding DCM to the mixture to make it thinner.




What a fine day for chemistry this is.
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LabRatNW
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[*] posted on 25-11-2009 at 17:29
Nitrating a poly alcohol.


I was going to use a sugar-alcohol (similar to Xylitol, maybe? Did you miss the label of the thread?) with H2SO4 and KNO3. All I needed to know is if it will work in place of NH4NO3, I don't see any reason it shouldn't... but if someone that has HE synth experience has had issues with it, I'd like to know.
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[*] posted on 1-12-2009 at 13:15


Issues noticed from experimentation:

1.) Mixed solution of H2SO4 and solid nitrate until clear, then refrigerate until at least 10C. Mix the solid nitrate extremely well! DO NOT have materiel floating in solution. One of the stumbling blocks is that often the KNO3 is impure and foreign matter becomes problematic when such a "Big Bertha" activity like a nitration is the objective. If the material is prilled, crush till extremely fine then mix w/ H2SO4 at a slow rate. The result should be a clear solution. This should be maintained at 10-15C.

2.) Most often the addition speed of the material to be nitrated is the contributor to success or a run-a-way. If you need to - use a time keeping mechanism to make sure the addition is not too fast NOR is it too much in weight/quantity. Materials such as these (sugar alcohols) MUST be kept moving with in the cold solution and the addition should be sub-gram level. Suggestion would be the larger stir-bar in oval shape as that will continue to stir when the solution becomes thickened. If that is unavailable, use standard stir-bar at higher speed but be VERY careful to never have nongranular or "lumpy" material. Use old coffee grinder if need be (on both nitrate and material to BE nitrated).

Note that USP grade KNO3 goes into solution quickly and without trace. Test KNO3 and see if coating of clay, etc is seen in nitrate/water solution. If foreign mater exists, clean it out or use another source of nitrate (same for any solid nitrate obviously)

3.) Less NaNO3 is needed than KNO3 & less KNO3 than NH4NO3 to achieve the similar level of mixed acid solution.
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[*] posted on 30-3-2011 at 04:58


So has anyone successfully synthesized Xylitol Pentanitrate with Xylitol and the same ETN synthesis procedure?



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quicksilver
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[*] posted on 30-3-2011 at 09:47


There would generally be minute differences in nitration of previously solid polyols. Elements may exist as time of exposure, mixed or direct HNO3 exposure, temperatures, etc. Some maintain solidity while others reach a viscous syrup-like consistency at a certain level of nitration. Check Federoff (PATR): I believe there are specifics therein regarding Xylitol & it's idiosyncrasies.



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