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Author: Subject: Tri-Nitrocellulose
Rosco Bodine
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[*] posted on 2-7-2005 at 12:24


So don't leave us wanting for the details of the methods for syntheses which you tested :D

I have wondered if the nitration might be optimized in ways more like for
nitrostarch , given the physical similarity .
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[*] posted on 3-7-2005 at 14:15


Nitration of MCC is straight forward and easy using about any of the typical nitration schemes.

Doing some research on MCC will show that it is formed by the chemical removal of the amorphous cellulose regions with mineral acid usually HCL, leaving practically pure crystalline alpha cellulose. These regions gelling are usually the problem that people have when using incorrect ratios of nitrating acids. Nitric acid will cause degradation of amorphous cellulose and it will get soft and gooey hindering the nitration itself and making handling the product difficult or impossible. MCC is very forgiving in this regard. An incorrect or weak nitration mix will result in a visibly identical process as well as finished product except for the actual nitrogen content. In essence, you really can’t screw it up.

I find it most convenient to use an alkaline metal nitrate in combination with H2SO4. Typically when nitrating cotton, mixed nitric and sulfuric are preferred since cotton absorbs so much of the acid liquor you normally need an excess of acid to keep it physically in the solution, separated and able to give off its initial heat of the reaction so as not form hot spots or cause a run away. Using a nitrate/H2SO4 mix to nitrate cotton usually just increases the viscosity of the mix thereby making it necessary to use even more sulfuric. You will find that it is most easy to load the acid mix with more MCC than can be nitrated by any given amount of acid. Most amateur nitrators will enjoy this inherent efficiency of their hard to come by acid.

Separation, washing and quenching, as I said in previous post, is a breeze. Upon standing, the MCNC will rise to the surface of spent acids in a semi soft mass that can be scooped out with ease and quenched in water. This mass carries very little acid with it in contrast to cotton. When said mass is plunged into water, the acid/water ratio falls below the nitration region very quickly thus greatly reducing the de-nitration of the product during the first few seconds of washing. As you know nitration of cellulose is reversible and is equilibrium depending on the strength of the acid mix or its water content. If the cotton is in a large mass, or if one is slow in getting the cellulose washed, or plunges into an insufficient amount of cold water, the N content will begin to decrease until dilution of acids falls below a certain level. MCNC typically will result in higher finished N contents with a given acid mix compared to cotton or wood derived cellulose. Since MCC is not tubular cellulose structures as is cotton, it is less likely trap formed metallic sulfates as well as acids, so neutralization is a snap. I wash with cold water a few times in a fine screen and then a short boil. I will admit that I haven’t done extensive research of storage stability as of yet so your results will almost certainly vary.

Time to reach equilibrium depends both on the strength of the nitration mix AND the particle size of the MCC. 10 to 30 micron material will complete in a matter of minutes where as 200 micron material may take a few days. Think of each MCC particle nitrating from the outside in. If you use coarser sizes, 50+, and shorter soak times, you will have overall lower N contents. At this point I must tell you that my aim is not highly nitrated material. I make pyrotechnics and my goal is a high nitrogen fuel, not propellants or explosives. For my purposes 10 to 11.5 percent nitrogen is best. Therefore I have tuned my processes to that end. I prefer KNO3/H2SO4 because I have a lot of both, and also want to keep sodium to a minimum.

All that being said, I don’t envision everyone falling in love with MCNC, especially this crowd. Anyone who has played with gun cotton is usually enamored by a small quantity burning with a pleasing thump when touched off with a flame. Compared to fibrous NC cotton, MCNC will burn much slower than a similar quantity of NC cotton. For use as a loose propellant, such as how gun cotton is employed in toy and novelty items, MCNC would be useless. However, if one wants to mix NC with other powders or liquids or if one aims to compress it or machine it… MCNC is a dream!

P.S. MCC is said to be able to hold a great amount of liquid and still be compressed in a dry mass. This should be something quite of interest to those who would seek to use MCNC as a carrier of other energetic liquids. However, I have done no research in that area.

Enjoy!
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Rosco Bodine
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[*] posted on 3-7-2005 at 15:13


Yeah I did some reading on the MCC product called Avicel . And I need to correct what I said earlier about cellulose flour being the same thing because it is not . Evidently cellulose powder or flour
is simply finely granulated sawdust basically which has been leached of nearly everything else but the cellulose it contains . It is however an amorphous material not as dense as microcrystalline cellulose . Further treatment with acid is
required to strip away the exposed fiber layers which surround the core nuggets of crystalline cellulose averaging about 250 molecules of cellulose per crystal .

I think a similar process is known for a material called " cyclodextrin " , the nitrated form of which is used in military explosives . I have a patent on this material somewhere , and MCNC seems
very similar . It may be the cyclodextrin which has the 8 unit ring structure . I'll try to dig up the patent if anyone is interested .

MCC is used also as a chromatography absorbent . It does form thixotropic gels but is actually insoluble , forming a dispersion and not a true solution .

It would be intersting to find out how sensitive compressed MCNC is to initiation , and at what lower percentage limit it may function as a binder for lead azide , silver azide , ect. Since it sounds like it is pressure flowable and tough , it may make an exceptional binder for other
materials . Caseless ammunition is a great idea , and caseless detonators too ,
where the case itself participates in the detonation . Some interesting ordnance could be contemplated for stealth applications , since the structure of a glide bomb for example , including the circuit boards for the electronics would every part be a contributor to the detonation , and there would be very little left as a signature to provide any intel on what it was or from where it came .
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[*] posted on 4-7-2005 at 14:14
Caseless ammunition


IIRC, the HK G11K3 was experimented with by (then) West Germany's special forces.
Bore diameters include 4.7mm and 4.92mm. It appears to have largely abandonded
because the rounds could autoignite after 7 or 8 shots were fired.




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[*] posted on 7-7-2005 at 05:56


Re microcrystalline cellulose:

I was thinking that maybe regenerated cellulose (see this) solubilised with the cuprammonia solution could be a good target for nitration; i.e. it could be either neutralised by pouring the whole mix into a large amount of water, and filtering the cellulose as single molecule fibres, or alternatively spinning fine fibres from it (i.e. pressing it through a syringe into the neutralisation solution).

In any case, this may be something to play with, it may have different properties from the normal NC.




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[*] posted on 11-7-2005 at 01:07


In purifying nitrocellulose, to extract the unnitrated cotton from the acetone solution it must be used a coffee filter or filter paper?
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[*] posted on 16-7-2005 at 12:52


nc dissolved in acetone is very dense, my dubt was if unnitrated cotton would obstruct filter paper, because i tried with a coffee filter and a very small quantity of nc dissolved passed... i needed to know if my nc was awfully nitrated or if filtering metod was mistaken... excuse me...
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[*] posted on 10-8-2006 at 00:26


I'm still not clear on what specific H2SO4/HNO3/H2O/cellulose mix to use to get a nitration level optimal for making NC that will gell NG well.



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[*] posted on 10-8-2006 at 09:28


Check out Boomer's post (6th from top) in the Nitrostarch thread in the HE section over in APC.

Not sure if I've seen you over there so you may not have access but if you send Mumbles a PM...

It relates to the quality of NC (from how well it burns and hence nitrogen content) that is gotten using varying ratios of acid, nitrate and starch and IMO could be extrapolated for use in a nitrocellulose synth.
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[*] posted on 11-8-2006 at 05:47


Generally speaking, higher temps and longer soaking give better soluble NC (for a given N content).

Instead of *diluting* the precious nitric to get lower nitrogen, try re-using the mix. It takes so little cotton because of the bulk that you can use it at least 4 times. This is limited more by the losses you cannot squeeze out after each use, than by the dilution from reaction water.

This way you have some fast but insoluble stuff for other things, and from the later batches some soluble NC. Way better acid usage IMO.
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[*] posted on 14-9-2006 at 07:03


I also have made some nitrated cellulose (a.k.a. nitrocotton, but I know that is a bad name).

http://woelen.scheikunde.net/science/chem/exps/nitrocotton/i...

This experiment is easy to perform and fairly fool-proof. But now I'm wondering, could this also be done with perchloric acid instead of nitric acid? What if you mix 60 .. 70% HClO4 with concentrated H2SO4 and then press the piece of wadding into the liquid? Does it form the perchlorate ester, or does it explode, or nothing happens? If anyone has tried this, I would be pleased to read about the results. I could try it myself also, but then I first need to prepare a setup for really tiny amounts, my supply of HClO4 is almost gone and it is a chemical which is not easy to obtain :( (maybe I can obtain a small amount again, but that is not sure yet).

I did try the variation with chlorate (I have a reasonable amount of that), but that does not work. It simply is impossible to make a chlorate ester. I made a tiny amount of KClO3/H2SO4 mix and added a piece of wadding. The mix ignites on contact with the piece of wadding, giving a purplish orange flash and crackling noise.

[Edited on 14-9-06 by woelen]




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[*] posted on 14-9-2006 at 07:37


Perchloric esters of cellulose have never been obtained, I read somewhere.
I also can't see why it should work, as HClO4 is a much stronger acid than H2SO4. The HClO4 would catalyze the formation of cellulose sulfate, not the other way round.

On the topic of NC: A much better product is obtained if the cotton is boiled in 2-4% NaOH solution for a few hours to clean it from resins and cell plasma residues. It is then washed, dried and nitrated in the usual way. The nitrating acid can reach and wet the fibers better then.
This greatly improves the quality, stability and nitrogen content of the NC.




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[*] posted on 19-11-2007 at 09:40


I know this is off topic but I didn't want to start a new tread about it.
I have some cannon grade smokeless powder from WW2. It was in rods and plates and it is very hard. I grinded it to 1-2 cm pieces by putting it in a bag and hitting it with a hammer. But I want to grind it to 1-2 mm granules. How can I do that?




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[*] posted on 19-11-2007 at 12:11


That WAS pretty wildly off topic but what the Hell....I'd put it it water and use a blender. Depending upon whether it was glazed or not it may break into very fine particulate with a blender and be quite recoverable. Some of the long rod material was true Cordite (very high NG content: higher than todays canister powders!).

[Edited on 19-11-2007 by quicksilver]
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[*] posted on 19-11-2007 at 12:38


Quote:
Originally posted by quicksilver
That WAS pretty wildly off topic but what the Hell....I'd put it it water and use a blender. Depending upon whether it was glazed or not it may break into very fine particulate with a blender and be quite recoverable. Some of the long rod material was true Cordite (very high HG content: higher than todays canister powders!).


So if it is glazed it will be recoverable and if it s not it will be unrecoverable or?

What do you mean by HG?


And the powder was 60 years under water and still lives:)




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[*] posted on 19-11-2007 at 16:38


My bad, I meant NG. The original cordite had a great deal of nitroglycerin; more so than today's Bullseye. Well, if it's highly glazed via graphite and a related process the "stick" may be more resilient than if it were not. Only one way to find out - try it! Some time back some experiments were conducted to determine if it were possible to pull the NG out of the DBSP. It was determined that (if it were not too effectively glazed) ethanol or ethyl acetate were utilized - the NG could, indeed be brought back into solution and the solvent evaporated off. You see the glazing forms a sort of tough shell on the product.

I tried to find some source on this and from what I remember Bullseye has 46-48% NG (Alliant Corp)and Cordite from UK gov't sources had 55-57%. but I think it's printed on the canister as well.



[Edited on 19-11-2007 by quicksilver]
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[*] posted on 19-11-2007 at 22:15


There is extensive information on NG recovery from finished and semi-finished smokeless powder in Naoum's NG and NG Explosives. At the end of WWI. they had to do something to reclaim it for mining explosives, and developed techniques.
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[*] posted on 22-12-2007 at 18:56


Forgive me if this is a stupid question, but I have searched extensively and cannot find a definitive answer.
I know blasting gelatin is made using collodion nitrocellulose with a nitrogen content around 11-12%.
My question is, can nitroglycerin be soaked into cellulose hexanitrate,(I know there is controversy about what hexanitrate actually is), so let me just say cellulose nitrate with a high nitrogen %.
I have made cellulose nitrate that detonates well, so I presume it has a high nitrogen%,(guncotton).
Can I soak nitroglycerin into the guncotton in it's fibrous state, or is this a waste of time.
I have made nitroglycerin that worked very well, I simply soaked it into saw dust and it detonated fully with a small amount of HMTD.
I was thinking that soaking it into guncotton instead of saw dust would be more affective?




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[*] posted on 22-12-2007 at 19:30


Make sure your NC is fully neutral before you mix it with NG. I haven't mixed the two for a while but im pretty sure that NG will dissolve NC... Hence making it a jelly...
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[*] posted on 22-12-2007 at 19:37


I thought NC with a high nitrogen% (hexanitrate) was insoluable in NG?



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[*] posted on 23-12-2007 at 01:41


Could well be. I made some fresh NC this afternoon. I will go get some more glycerin from the chemist and see what happens.
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[*] posted on 23-12-2007 at 11:56


Yes NC with a nitrogen percentage above a number(13.5 or 14 ish IIRC) is insoluble in NG.
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[*] posted on 23-12-2007 at 13:33


Could it still be used as a medium to soak NG into or would it be pointless



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[*] posted on 25-12-2007 at 02:00


I think with the added NG through the NC you would fairly easily achieve a full detonation of both compounds. Using an explosive filler will be more powerfull than an inert one, say diatomous eath, saw dust, clay etc. For making the ammount of NC/NG dynamite that would be practical for my usues (I blast on a large property) the sheer size of a reaction vessel for NC synths would be impracticable. For a small scale go it though.
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[*] posted on 1-7-2008 at 11:01
Nitrocellulose question


Hello,
I Nitrated a cotton ball using a 50/50 solution of 68% nitric acid and 97% sulphuric acid. (nasty fumes btw)
I used an ice bath to slow it down when the reaction started to get a little frisky. I added the cotton ball all at once and submerged it in the nitration bath. It later occurred to me that i should have perhaps added it a little bit at a time to ensure proper saturation. I used a stirring rod to expel all of the air from the cotton ball while it was in the nitration bath but i am unsure how well it will turn out. It was in the bath for approx 7 minutes if that helps at all. My question is: Did i achieve enough saturation to fully nitrate the cellulose or do you think that it will turn out to be only partially nitrated?

P.S.
What should i do with the excess nitration solution? The best i could think of was to pour it in my backyard where there wasn't any grass, cover it with sodium bicarbonate and then pour water on it to dilute. I know this sounds like an EPA disaster but i feared it might corrode my plumbing.

[Edited on 1-7-2008 by Skrinkle]

Edit by Chemoleo: Please post in the appropriate thread next time, there is a search engine. Also, many of your questions can be answered by reading this thread (and other related ones) more carefully.

[Edited on 1-7-2008 by chemoleo]
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