Sciencemadness Discussion Board - Preparation of nitrostarch

Preparation of nitrostarch

madscientist - 21-5-2002 at 11:56

I am curious about nitration times. How long will it take to fully nitrate starch at about 0-5 degrees Celcius? Also, how necessary is it to stir it constantly? I have some other questions about the properties of nitrostarch.
Is it soluable in organic solvents like acetone? I believe it would be, but I would appreciate a confirmation of this prediction.
Just how sensitive to shock is it? I'm afraid I cannot trust Megalomania on sensitivity of various explosives (his site said that potassium picrate has "low sensitivity" which is preposterous). Will it explode from fuse ignition, or must it be detonated with a detonator? I've heard rumors that it merely requires flame.

Madog - 21-5-2002 at 11:57

have you ever made potassium picrate? probaly not i have made it and it is not shock or friction sensitive (to hammers and grinding)
in my opinion it is realy only good for lighting unconfined (looks cool and makes a cool noise) its realy just a novelty i have yet to confine it to make it burst the container (it has like no bristancy when used as a LE).

madscientist - 21-5-2002 at 11:57

Hrm, I sure have heard otherwise from reputable sources, such as chemistry books and encyclopedias. They said it was dangerously sensitive.

Polverone - 21-5-2002 at 11:58

It is difficult to authoritatively pronounce the sensitivity of home made energetic materials. Quality control is very difficult. Atmospheric humidity, material humidity, trace contaminants, particle size, etc. may all affect sensitivity to initiation and the vigor of post-initiation action. If you're concerned about safety (and you should be), it's best to err on the side of caution. On the other hand, it can be a letdown to anticipate a chest-thumping explosion and have a little fire instead.
Madog, I'm curious how dry your K picrate was. It's not exactly something that I'd dry in an oven, but a few days in a sealed plastic bucket at room temp with a tray of calcium oxide ought to suck up any moisture nicely. I would expect it to make a respectable low explosive, even though it might not be terribly sensitive to initiation. If you were trying to use the picrate as an LE and failed, did you ever try making picrate whistle mix with it (supposed to be pretty violent for a pyro comp)? I'm not exactly *endorsing* this idea, but it might be worth a try if you were disappointed by the explosive nature of the pure picrate.

madscientist - 21-5-2002 at 11:58

Important information... As one should know, virtually all industrially produced acetone contains benzene, an extremely dangerous carcinogen. That is the reason I no longer like to make acetone peroxide; I do not like the idea of exposing myself to a carcinogen so dangerous as benzene. A substitute for using acetone to dissolve nitrostarch is ethyl alcohol (sold as "denatured alcohol", which contains small quantities of very toxic methanol).

Polverone - 21-5-2002 at 11:59

I have seen many different brands of acetone (talking paint store grade, never ordered it from a chem supplier) and some containers warn that they contain small amounts of benzene; others do not. For what it's worth, the cheaper brands seem to have this warning more often. The acetone I currently have in my lab ("Klean-Strip" brand) does not carry such a warning. It claims "100% acetone" on the side information panel. I don't know if this is truly purer than cheaper stuff or if the manufacturer is just less upfront about the hazards.
Oh, and here's something interesting: I just found out today that nitrile gloves (which are what I usually use) have very good resistance to most caustics and solvents, but not to ketones (like acetone). Thought that was interesting. Of course, I've had my bare arms up to the elbows in acetone before and it didn't bother me... Giving up the production of acetone peroxide because you're worried about trace amounts of benzene seems a little backwards to me. I think making primary explosives is likely to kill you much sooner than your solvents. It's like giving up motorcycle racing because you're worried about the exhaust fumes.
Acetone is so useful that I doubt it'll ever disappear from my lab (unless the law takes it away). If you are willing to pay a large premium for safer solvents, you can get 95% ethanol (no methanol) at liquor stores, under various brand names. I paid nearly $20 for 750 mL of the stuff. I got it for those rare times when small amounts of methanol might pose problems. Of course, that is tougher if you aren't 21 yet. Also, on the acetone front, you could try e-mailing different vendors/mfrs until you find one that sells benzene-free acetone. Just say you work with acetone on a regular basis and you're worried about long-term exposure to benzene, even small amounts.

Madog - 21-5-2002 at 11:59

it may have some water in it (it seems dry but it has only been air dried) i have tried mixing it with KNO3 with no luck when lit unconfined it looks like a REALY good LE but when confined it won't burst a thin paper tube (but it will crack and shoot the fuse away) the water content may be the problem
oh my god! i just went into my lab and was able to set it off with a hammer for the first time! jese well i guess it is pretty sensitive(but not that mutch)

madscientist - 21-5-2002 at 12:00

What the hell is going on? This is very strange. I had my sludgey mixture of nitrostarch and starch ready for harvestation. I had heard that acetone works well as a nitrostarch solvent. However, my chemistry books recommended using ethyl alcohol as a solvent, so I used some denatured alcohol at first. I managed to dissolve a good percentage of the nitrostarch / starch mix, and poured the liquid into a filter, leaving the undissolved solids in the beaker. It started filtering well. Then I decided I would try dissolving the remaining nitrostarch / starch mix with acetone (about one third of the original amount remained). It seemed to dissolve faster and better at first. I poured it into the filter (about a third of the denatured alcohol had run through the filter already). The speed of filtering dropped off rapidly. Now, about twenty minutes later, it has completely stopped running through the filter, even when stirred vigorously for the purpose of moving sediments off of the filter paper. There seems to be nothing out of solution. What the hell is going on? The only thing that I can think of is that there is some reaction taking place between acetone, ethyl alcohol, nitrostarch, and starch; but I have no clue what as of yet. Any ideas?

madscientist - 21-5-2002 at 12:01

I still managed to get about ten grams of nitrostarch from my attempted nitration of twenty grams of starch. I believe the reason for these terrible yields is that I had the nitration temperature far too low (one degree
Celcius, it probably should have been more like ten degrees Celcius). Nitrostarch is very stable, when i place a small piece of it on concrete, no matter how hard I hit it with a rock hammer (believe me, you can hit something HARD with a rock hammer, so hard you can crack or chip sidewalk concrete) and it simply wouldn't go off. When heated by flame it flashed into a small ball of orange flame. Soon I will attempt to detonate it.

PHILOU Zrealone - 21-5-2002 at 12:01

Looks ok to me; filtration via paper filter always goes slower and slower and slower!
For sure the impregnated filter with alcool and aceton is the reason! You should have stick to one solvant!
Or start initially with a mix of the two (althrough, I suspect aceton is a better solvant than ethanol).
The procedure must be caried out this way:
Add to the crude solid HE some aceton or hot ethanol (50°C), until dissolved. Filter (hot in the case of ethanol); add a little pure solvant when it starts to go slower to wash everything. Then add cold neutral or slightly basic water under stirring until the HE precipitates/cristallises out. Filter again! This time the HE is purer and contains less impurities (HNO3 included-maybe a little base stil in of course). repeat as much as you want (yield will decrease but purity will be higher).

PH Z

PHILOU Zrealone - 21-5-2002 at 12:02

Sensitivity of picrate is in most cases higher than picric acid itself (what is about as sensitive as RDX). Only NH4 salt, NH2-NH3 and Na salt are moderately sensitive, then K salt comes (Na, K, NH2-NH3, NH4) salts are difficult to detonate unconfined!
Other picrates can be extremely sensitive primaries Ca salt comes to mind as being one of the worst!
Shock sensitivity tests with a hammer and a hand hit are very unreliable!
Shock sensitivity is generally expressed as the energy provided by a falling weight (in kg) from a given height (m).
Ex: NG has a sensitivity of 0,2Nm; this means that in 50% of the cases (13 trials on 26!!!) the tiny 1-2mg sample wrapped in Al foil and placed under a percussion armor and on an iron block will take fire, deflagrate or detonate with a sharp crack under the blow of a falling weight of 0,2N from 1 meter height!
0,2N is equivalent to 0,020387 kg (so approx 0,02kg or 20g!
N is the unit of force expressed in Newtons; typicaly a weight standing on a scale press on it with the gravitational acceleration (g= 9,81 m/s*s) and thus 1kg has a weight force of 1kg*9,81m/s*s= 9,81 Newtons)
This value is often rounded to 10N/kg!
So NG with its 0,2Nm is quite sensitive since it is the force excerced by the fall of 20g from a meter and by the magical of mathematics and physical energy conservation:
F(20g/1m) = F(2g/10m)= F(200g/0,1m(10cm)) = F(2kg/0,01m(1cm))
So 20 g falling from 1 meter has the same energy of impact as 2000g (2kg) from 1cm...you easily understand why people are not very hot to carry NG as a liquid!

Now back to picrates:
Picrates are in that range of sensitivities some are below 0,2Nm some are a little over, but they are solid, while NG is a liquid; when home made test is made with NG, it splashes all arround-but if you absorb it on toilet paper detonation will occure much easier since it retain the NG wel in the travel of the hammer!
So basically an idot would say...hey my NG didn't explode when I hurted it with a hammer...he forgot that point and the fact it is possible that under a given shock, the explosive don't go off (shock sensitivity are made 26 times at a same height with the same weight!); but that next time it will...as it was the case of our dear Madog!
So as said Polverone: better consider explosives to be as sensitive as NG...your life hangs on it!

PH Z

madscientist - 24-6-2002 at 11:01

I have found that the runaway nitration temperature for nitrating starch in concentrated mixed acid is about 46C. If the temperature slides above that, you're going to have to drown the nitration in water. Trying to bring the temperature back down with an ice bath will work about as well as trying to extinguish a beaker filled with burning thermite by placing it in an ice bath.

[Edited on 24-6-2002 by madscientist]

PHILOU Zrealone - 8-9-2002 at 11:32

Here is to reply to MadScientist question!

(p253- Explosives 4th, revised and extended edition by Josef Köhler /Rudolf Meyer)

Nitrostarch:
(C6H7O2(ONO2)3)n
Pale yellow powder
Empirical formula of the structural unit: C6H7N3O9
Oxygen balance at 12,2% N:-35%
Density: 1,6g/ccm
Maximum value attainable by pressing 1,1g/ccm
lead block test: 356 ccm/10g
Deflagration point: 183°C (361°F)
Impact sensitivity: 1,1 kp m = 11 Nm (1,1kg from a meter)
Unsoluble in water and ether; soluble in ethanol/ether mixes and in aceton.
Nitrostarch with various N contents (12-13,3%) is prepared by nitration of starch with HNO3 or nitrating mixtures.The resulting crude product is washed in cold water and is then dried at 35-40°C.
It ressembles nitrocellulose in several respects, but owing to its poor stability, difficulty in preparation and hygroscopicity, it is not used anywhere outside the USA "Headache-free industrial explosives are based on nitrostarch".

Those values are for the 12,2 N contain, not for the 13,3% that will be denser, and display higher sensitivity, and power!
Anyway as I have proved already elsewhere:
Polymers of a monomer display lower or equal sensitivity to shock/heat; higher performances and higher densities.
Thus nitrocellulose being a higher polymer of glucose than starch NC>NS in explosive properties.Also it will be wise to wash the NS with Na2CO3 water since it is even less stable than NC towards moisture and hydrolysis!

PH Z

Trotsky - 13-4-2013 at 21:56

Does anyone here have much experience with nitrostarch? Specifically I'm interested in it's ability to undergo DDT when confined, or is it like NC and very difficult to detonate without a primary?

I have an AN/Nitrokerosene mix (about 93:7) that I wish to detonate and I was hoping that NS might undergo DDT easily enough to detonate the ANNK. The more I read, though, the more I think it's unlikely to work well. I don't want to use peroxides but maybe a .1g of 5050 peroxide-starch blend atop 1g straight NS atop the ANNK would work well enough?

Fantasma4500 - 14-4-2013 at 06:35

benzene in acetone..
well if you want pure acetone it should be pretty easy... (:
vinegar + CaCO3 > calcium acetate
calcium acetate + ~160*C > acetone + CaCO3 (yes sorry for not giving the full chemical names etc. but you get the idea)
the CaCO3 can then be reused
but i dont really see the actual problem in trace amounts of benzene when handling deadly sensitive primary explosives? i mean you have a decent risk in your hands already..? (:

Trotsky - 16-4-2013 at 15:21

I don't think that anyone of meaningful intelligence is actually concerned with trace amounts of benzene.

So back to the point of the thread-

Is NS considered a primary, secondary or tertiary explosive? It seems like a secondary to me but I'm not entirely positive.

There's a lot of old patents on it, but not much truly scientific in nature.

ManyInterests - 8-6-2023 at 20:12

I decided to necro this thread (as I have done with many others) since I am also making nitrostarch. I am following the instructions in a video that I saw on it, but from what I've seen so far, it is the single most chillest and simplest nitration I've ever done.

I used 52ml of around 76% nitric acid and 76ml of H2SO4 and in my usual manner, I put them in a beaker after cooling both reagents to 0C, then I covered that beaker and put it in the middle of an salt water tub and let the whole thing freeze in my freezer.

I then measured out 15 grams of corn starch and added it by the teaspoonful at first, but I noticed so little temperature rise that I decided to dump the remaining 9 or 10 grams of the starch (not super smart, I know) but while there was a noticible temperature increase, it was most certainly not a runaway, the temperature was still below 0C and the temperature only rose by 10C before it stablized and began to drop again, so it around 5C and it took me around 35 minutes to add everything. I kept it in the ice block for a while (it needed to melt a little before I could get it out) and with constant stirring for 15 minutes I let the temperature rise (it rose very slowly, so I know it is stable and not running away) and I put it back in the ice block once to let it cool down again before removing it.

So far it's been out of the ice block for an hour and it has risen to ambient temperature (16C) and I am stirring it every so often. It is well past the point of any danger.

I plan on crashing the whole mixture in 1800ml of cold tap water and filter it off, then I will wash it several more times with water until I get no more acid in the filtered water. After that I will prepare a sodium carbonate solution and wash it in that as well.

I read that it will recrystalize in denatured alcohol quite readily AND that refluxing it for a while in alcohol will also make for an extremely pure product. I will do that once I air dry the nitrostarch.

Edit: So after letting it drain in the filters overnight, I had washed them until the pH came as neutral, I decided to do something that I heard others do... boil the nitrostarch in a bicarbonate/carbonate solution. So I made 2 liters of waters with 2 tablespoons of sodium carbonate and brought it to a boil and using my 2 liter beaker, I put everything in it.

I then tried to heat it on my mantle... but I started to hear some bumping. I had no idea why, but I immediately stopped heating and got it off the mantle. I'm waiting for it to cool to room temperature and everything to settle down before filtering and washing again. I am taking no risks with this.

This also does make me question whether a reflux with ethanol is necessary. Maybe a recrystalization, yes, but not reflux.

Edit2: I've decided that boiling nitrostarch is a bad idea. from the dark brown patch at the bottom of my beaker, I think some of the nitrostarch may have popped or burned. From future synths I will only use hot solutions of carbonate with urea as a 2nd wash and NOT boiling or boil the nitrostarch in solution. For recrystalization I will only use warm 95% ethanol and not reflux it. I think I lost some yield as a result of my boil attempt.

[Edited on 9-6-2023 by ManyInterests]

[Edited on 9-6-2023 by ManyInterests]

unionised - 9-6-2023 at 09:39

Quote: Originally posted by madscientist

Important information... As one should know, virtually all industrially produced acetone contains benzene, an extremely dangerous carcinogen. That is the reason I no longer like to make acetone peroxide; I do not like the idea of exposing myself to a carcinogen so dangerous as benzene. A substitute for using acetone to dissolve nitrostarch is ethyl alcohol (sold as "denatured alcohol", which contains small quantities of very toxic methanol).

I realise this is a bit off topic but...
You are going to avoid acetone because it might contain benzene.
But you are OK with ethanol.

How many people do you think have got cancer from the benzene in acetone, compared to how many have got cancer from ethanol?

ManyInterests - 10-6-2023 at 22:03

I like you responded to a 21 year old post!

Anyway, I'm giving an update. I haven't recrystalized my nitrostarch, but I did get a yield of around 12.88 grams. What happened is that I accidentally dropped some starch on the ground from the bag I was storing it in. I did add another teaspoon to the bag, but I didn't know how much I lost.

I did a slight burn test on some and they burned very quickly and very well and with NO residue! I think a recrystalization might be needed to ensure further purity. But maybe I'll do that when I have another batch made to see how good of a yield I can get when I don't lose any starch.

Quote: Originally posted by Trotsky

I don't think that anyone of meaningful intelligence is actually concerned with trace amounts of benzene.

So back to the point of the thread-

Is NS considered a primary, secondary or tertiary explosive? It seems like a secondary to me but I'm not entirely positive.

There's a lot of old patents on it, but not much truly scientific in nature.

Just to mention it, the only use of nitrostarch I found anywhere was a mention in wikipedia that it was used as an explosive filler in hand grenades. Which country's hand grenades and how many of them used nitrostarch instead of TNT is unknown

According to TM 9-1300-214 (military explosives) they do have a section on nitrostarch and say that how it is made is guarded as a trade secret. It's power is reliant on its nitrogen content. More nitrogen = more power. It is less sensitive than nitrocellulose.

They mention that excess nitric acid is needed in the nitrating mixture to allow for a higher nitrogen content, that to make 12.75% nitrogen nitrostarch, you need a nitrating mixture of 38% nitric acid and 62% sulfuric acid.

My nitric acid was above 75% and I used 40% of it in the mixture. I am guessing that would mean I should have a nitrogen content just above that, which is good because that is the rated commercial grade.

Nitrostarch alone is often not used, but it is mixed with other stuff. What are those other stuff? They don't say. But one thing I find fascinating is that it is non-freezing, meaning if a dynamite is made with it using nitroglycerin it will not freeze. Allowing it to be used in ultra-cold climates like the Arctic or Antarctic.

A recrystalization is also seen as not being 100% necessary, but they did mention using a bit of ammonia in the water it is crashed into. I didn't use ammonia, but I gave it two crashes, one in pure water, and a 2nd in sodium carbonate solution. I think this is sufficient to remove any and all acids. I also washed the ever living hell out of it with additional cold water both times.

[Edited on 11-6-2023 by ManyInterests]

[Edited on 11-6-2023 by ManyInterests]

[Edited on 11-6-2023 by ManyInterests]

Microtek - 11-6-2023 at 23:06

A mixed acid with 38% nitric and 62% sulfuric does not contain any water. If your nitric was 80% concentrated, your mixed acid would contain 8% water (if your sulfuric acid was 100% conc.)

I think you will find it is difficult to recrystallize NS for the same reason that it is difficult to recrystallize NC - it forms a gel or viscous fluid when dissolved in acetone, especially if it is not quite evenly nitrated.

ManyInterests - 12-6-2023 at 20:58

Quote: Originally posted by Microtek

A mixed acid with 38% nitric and 62% sulfuric does not contain any water. If your nitric was 80% concentrated, your mixed acid would contain 8% water (if your sulfuric acid was 100% conc.)

I think you will find it is difficult to recrystallize NS for the same reason that it is difficult to recrystallize NC - it forms a gel or viscous fluid when dissolved in acetone, especially if it is not quite evenly nitrated.

In that case, I won't bother trying to recrystalize it. I think it is pure enough.

And that's for the information on the composition of the mixed acids. I still would want to make the acid as strong as possible to ensure a high nitrogen content.

Microtek - 12-6-2023 at 21:49

You can do some other things to remove traces of acid. For instance, place the NS in a coloumn and let water run slowly through. The problem is that the trace acid is not only coating the outer surface of the NS particles, but also is contained within them. For this reason, the rate determining step of the washing is the diffusion of acid to the surface of the particles. Diffusion is a very slow process and is driven by the concentration gradient between the inner and outer environment (inside and outside the particles). For this reason you need to continually remove the acid in the "outside" environment by letting water stream through the coloumn. Otherwise, you will only reach an equilibrium where the outside and inside acid concentration is "equal".
In ages past, NC would be cleaned by placing the newly nitrated cotton in a small river or stream for several weeks to accomplish the same thing.

It is a good idea to aim for a low water content in your mixed acids, and also to ensure a sufficient excess of the acids. Water is produced in the reaction along with the NS, just as with any other nitration. This means that the concentration of the mixed acids drops as the reaction proceeds, so you need some excess capacity for water scavenging beyond the initial water content.

Laboratory of Liptakov - 13-6-2023 at 07:50

The highest solubility of moderately nitrated nitrocellulose (12.2 - 12.8N) is in acetone, with a water content of 11% (Urbański research). This water may contain dissolved baking soda (NaHCO3). Maybe even a saturated solution of this baking soda. Nitrostarch is soluble in acetone as well. And its solubility can also be highest at 11% water content. It follows that the neutralization of nitrostarch can be carried out at the molecular level (i.e. in a clear solution) using water containing NaHCO3. By further adding the aqueous solution, a limit is reached where the nitrostarch starts to precipitate. By setting suitable conditions and suitable solvents such as acetone and ethanol and water, it is possible to prepare completely neutral nitrostarch. The disadvantage of this method is the large excess of solvents. But it's better than 14 days in the creek. Complette guide for NC: https://www.youtube.com/watch?v=oVZkPWxj5WE&t=49s

Microtek - 13-6-2023 at 09:15

I tried your method LL, but my NC does not dissolve so cleanly in acetone. I'm sure the reason is that mine is not as uniformly nitrated as your (commercial?) NC, but I would guess that will be the case with most home made NC or NS. Would be nice to be proven wrong though - your powdered NC looks very nice.

ManyInterests - 13-6-2023 at 10:43

Quote: Originally posted by Laboratory of Liptakov

The highest solubility of moderately nitrated nitrocellulose (12.2 - 12.8N) is in acetone, with a water content of 11% (Urbański research). This water may contain dissolved baking soda (NaHCO3). Maybe even a saturated solution of this baking soda. Nitrostarch is soluble in acetone as well. And its solubility can also be highest at 11% water content. It follows that the neutralization of nitrostarch can be carried out at the molecular level (i.e. in a clear solution) using water containing NaHCO3. By further adding the aqueous solution, a limit is reached where the nitrostarch starts to precipitate. By setting suitable conditions and suitable solvents such as acetone and ethanol and water, it is possible to prepare completely neutral nitrostarch. The disadvantage of this method is the large excess of solvents. But it's better than 14 days in the creek. Complette guide for NC: https://www.youtube.com/watch?v=oVZkPWxj5WE&t=49s

That is good. Because when I originally crashed my nitrostarch in 2 liters of cold tap water, after filtering and washing again and again I recrashed my nitro starch in another 2 liters of sodium carbonate solution (not bicarbonate) but that should work just as well. Was it crashed again once it was dissolved in acetone or what?

Laboratory of Liptakov - 13-6-2023 at 11:36

It's just a suggestion of a reaction to neutralize nitro starch. The method is not tested for nitro starch. The basis of everything is that the nitro starch is completely dissolved in acetone. Afterwards, nitro starch can be acted upon by various basic substances. For example, NaHCO3. And even without the water content in the solution. The basic preparation is on the wiki: https://en.wikipedia.org/wiki/Nitrostarch

ManyInterests - 13-6-2023 at 21:08

They did mention ethanol and acetone in that article. This is where I got the idea of refluxing it in ethanol, but the bumping I got when trying to boil it in carbonate solution made me not want to do that.

BTW, on a slightly off-topic note. I spent the last 24 hours making a lot of ammonia. I ended up with 1000ml of 24% ammonia solution! Is this concentration sufficient to make CHP and other stuff you make that calls for ammonia?

Laboratory of Liptakov - 13-6-2023 at 21:41

Yes, 24 % is ideal concentration for any purpose with relatively low evaporation at 20 C (or lab. temp.) And of course ideal for preparation TACP in rolling Liptakov´s container.

ManyInterests - 23-8-2023 at 18:50

I'm bumping up this thread again for one more question:

How does one determine the nitrogen content of the nitrostarch? I am away that lower-nitrogen nitrostarch has a weak detonation velocity (only around 1000 m/s) while high nitrogen content (around 14%) is around 6200 m/s, which is close to TNT.

What needs to be done in order to make sure you have higher nitrogen nitrostarch? More nitric acid and higher concentration nitric acid to sulfuric acid?

Is there any uses for nitrostarch in a lower nitrogen content than a higher one? For example I did read that nitrostarch is used as a binder for some liquid explosives, such as methyl nitrate, would lower nitrogen content nitrostarch be better for that or not?

Laboratory of Liptakov - 11-9-2023 at 03:06

Because nitrostarch is insoluble in water, but soluble in ethanol and acetone, is possible after nitration (with unknown %N) use the methode PLM.
Starch stay in solution, but all others with high % of N will be precipitated... :cool:

https://www.youtube.com/watch?v=oVZkPWxj5WE

[Edited on 11-9-2023 by Laboratory of Liptakov]

Microtek - 11-9-2023 at 23:25

You could also do a classical combustion analysis:

A sample of precisely known mass is mixed with CuO in excess and taken to red heat. This converts the sample into CO2, NOx, N2 and H2O (and possibly O2). A known volume of nitrogen gas (or dry air) from a syringe is used as a carrier to lead the combustion products through heated copper gauze (to reduce NOx and O2), alkaline solution to absorb the CO2 and a strong drying agent to absorb the water. All that remains is nitrogen and this gas is lead into an inverted measuring cylinder filled with water to measure the volume of dinitrogen. Now you can calculate the nitrogen content of the sample (but you have to do a control run without sample to find out the displacement from the carrier gas).

ManyInterests - 13-9-2023 at 03:47

Quote: Originally posted by Laboratory of Liptakov

Because nitrostarch is insoluble in water, but soluble in ethanol and acetone, is possible after nitration (with unknown %N) use the methode PLM.
Starch stay in solution, but all others with high % of N will be precipitated... :cool:

https://www.youtube.com/watch?v=oVZkPWxj5WE

[Edited on 11-9-2023 by Laboratory of Liptakov]

Sounds like a much easier way than combustion analysis!

Also afterward, I can let the ethanol and acetone solution evaporate and I can still keep the lower N% stuff. Will this work as a recrystalization, too?

For the ethanol, I assume it is best to use 95% ethanol, correct? Absolute if possible.

edit: Also this is exactly what I need to make gun cotton into double base smokeless powder... I need it in fine powder form and I always wondered how it is done.

[Edited on 13-9-2023 by ManyInterests]

Laboratory of Liptakov - 13-9-2023 at 22:12

Each precipitation requires multiple tests of its own. The PLM method may not always work perfectly and exactly according to the instructions. The basis is a test of 1g (dry weight) of nitro substance + different ratios of acetone and alcohol. (before adding H2O) During the process, it is possible to carry out neutralization at the molecular level with NaHCO3. Even before precipitation. It's all about playing with liquids. Is possible use any ethanol and any acetone. :cool:

Microtek - 14-9-2023 at 00:04

Quote:

Sounds like a much easier way than combustion analysis!

Certainly. But the accuracy of your analysis will be lower. It all depends on what you are trying to achieve...

Solubility of nitrocellulose (and probably nitrostarch as well) is not a simple linear function of the degree of nitration. Very highly nitrated NC has a lower solubility in acetone than NC with a somewhat lower N%. There could also be assorted types of entrainment issues to contend with.

[Edited on 14-9-2023 by Microtek]

ManyInterests - 14-9-2023 at 14:22

What I am trying to achieve, ultimately, is to make sure that the nitrocellulose and nitrostarch that I make is of sufficiently high nitrogen content. I'm sure that in one of Urbanski's books they have some information on making high vs. low nitrogen NC.

I assume that making smokeless double base gunpowder will require high nitrogen NC (can nitrostarch be used for that as well?). I'm specifically looking to make powders that are appropriate to use with pistols, such as 9mm rounds.

DennyDevHE77 - 14-9-2023 at 21:19

The ability of nitrostarch to form solid colloidal solutions with nitroesters is much less than that of NC. Therefore, nitrostarch in its independent form is not suitable for the production of smokeless powder, only as an additive to nitrocellulose.

In general, all nitrocellulose is divided into colloxylin (10.7 - 12.2% N), pyroxylin No. 2 (12.2 - 12.5% N), pyroxylin No. 1 (13.0 -
13.5% N). And colloxylin is excellent for gunpowder, it is more easily plasticized with nitroesters, and it generally contains a fairly large number of compounds.

And yes, in the fourth volume of Urbanski (pages 577-599) it is briefly written about gunpowder