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mewrox99
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[*] posted on 7-10-2010 at 02:42
Nitrocellulose Help


50mL of 98% Sulfuric acid was measured out in a 250mL beaker and placed in a NaCl/Ice bath. 20g of ammonium nitrate was added in tea spoon sized portions with stirring.


The nitrating solution

After letting the Ammonium nitrate dissolve completely and the mixture cool. Enough cotton to fully absorb the nitration mixture was added.

nitrating solution.png - 421kB

After 25mins of being left alone, the cotton balls were taken out. Washed, neutralized, and then washed several times after neutralization

After 8 hours I took a some of the smaller dryer pieces and put a small chunk onto my hot plate on full blast. It did ignite but left quite a lot of ash and burned slightly faster then cotton about 10sec compared to split second nitrocellulose.

Even direct heating with a pencil torch led to disappointing combustion

Is it either:

A: I'm being impatient and should give it at least 24 hours to dry

B: The excess of cotton caused it to be under nitrated.


final product.JPG - 51kB

The final product



[Edited on 7-10-2010 by mewrox99]
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[*] posted on 7-10-2010 at 03:08


You need strong mixed acid to get satisfactory NC.
You have the H2SO4 and nitrate salts - all you're missing is a simple distillation apparatus . . .

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mewrox99
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[*] posted on 7-10-2010 at 03:27


I've seen videos of people with fairly good NC from simply nitrate + conc H2SO4

Like this for example http://www.grassrootsdiy.com/NC.htm

His seems ok.

Anyway when I next get some money I'm gonna get some HNO3. I get 5L of the 70% for NZ$60 shipped
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[*] posted on 7-10-2010 at 05:16


try this (old lab notes):
a 3% soln of NaOH is boiled for 1 h with cotton balls in. then take the cotton and wash VERY carefully to eliminate every trace of hydroxide and dry. This step is optional but I think I did it to purify cotton from every resinous material and make the fibers more fluffy. Remember to "open" the balls while they're drying, I mean there mustn't be knots or strings it must be completely fluffy.
Nitration:
to 10 ml H2SO4 are added 6.7g dry pure NH4NO3 prills (I usually add all at once, just avoid breathing the vapor) and stir until everything is dissolved. When the temperature is dropped to 30-40°C (just a little warm) add a piece of 0.8-0.9 g of the cotton. Push and squeeze it in the nitrating mix until it looks like a uniformly wet mass. runways are not very probable and anyway with NC the risk of explosion is minimal but the NOx are nasty so, especially in the first 10-15 minutes keep checking it. Leave it in the acid mix for 50 min, maybe giving a stir from time to time.
then squeeze the NC from the acid and put it in cool water with carbonate or bicarbonate added. Squeeze and open the fibers very thoughtfully and keep adding the bicarbonate until it stops fizzling. Then wash again very thoughtfully with water. I made it dry using a hairdryer at low heat (at maximum heat once NC ignited WHOOOMP :) ). Again while it's drying keep opening the fibres so that when it's dry it is completely fluffy and without knots. It should burn pretty fast, maybe not with the THUMP sound but very fast anyway. If you want REALLY good NC that flashes with THUMP and makes you can "feel" the deflagration just nitrate your NC twice. I mean make it once, neutralise, dry and then nitrate it again like it was normal cotton. That KICKS ASSES :cool: good luck, have fun, be safe
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[*] posted on 7-10-2010 at 12:30


For some reason H2SO4/nitrate salt NC nitrations just don't seem to give the same results als H2SO4/HNO3 does. If you want good NC concentrated nitric acid is the way to go.

Another important note is to check the composition of your mixed acids closely. The nitration mixture contains H2SO4, HNO3 and H2O in certain proportions. There is a specific 'sweet spot' in wich NC of a high nitrogen content is formed, but there are also ratio's that give poor results. You should check urbanski for the charts. Stronger is in this case not always better. Therefore sometimes it's even necessary to add water in order to obtain faster NC. ;)
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[*] posted on 7-10-2010 at 13:41


I had the same problem with crap product. Have excess nitrating mixture relative to cotton. Dont put as much cotton as you can in, it is not efficient. This is all I got, but its what worked for me. I used both ammonium and potassium nitrate and they both work, just use less cotton, let it sit for at least an hour. In fact I followed a procedure on here, so search and you will see someone who did it.
But yeah, Im betting on incomplete nitration. Oh also dont keep it so cold, around 10-15 degrees c is good as you add cotton, then let it warm to room temp. This always worked for me. Try it a few more times, see how well you can get it to work;)
It is possible to get reasonable nitrocellulose from H2SO4/nitrate salt method, but using HNO3 is where its at:D

[Edited on 7-10-2010 by Magic Muzzlet]
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mewrox99
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[*] posted on 7-10-2010 at 19:22


Ok so I cool it with an ice bath when the AN is added. And then add the cotton and take it out of the ice bath.

I'll leave it in there for an hour. I'll post the results.

Which is better AN prill or KNO3 in a table salt like powder


[Edited on 8-10-2010 by mewrox99]
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[*] posted on 8-10-2010 at 00:10


You're all missing the correct answer. While some of your points are valid, it's not the reason for why it's performing so poorly. Mewrox99, your first point was correct. You need more than twenty four hours drying time. It's amazing how many people think they buggered up the nitration and toss out the product just because they didn't let it dry enough. Even after three days my nitrocellulose wouldn't burn completely great. The speed of its deflagration would increase for a fortnight if I let it dry inside. Let's not forget, cotton contains at a minimum 5% moisture by weight.

You said you neutralized it, that's good. Acid soaked NC will never dry well. Perhaps even do more neutralizing washes would be a good thing. Acid can be trapped inside the fibers, ringing it out and ensuring it is completely neutralized is very beneficial. My last synthesis I did three bicarb solution washes, making sure I really work the fibers of the cotton to ensure there's no residue acid in it. You have to make sure you excessively wash the product.

Back to drying:

Allow it to dry. It will take at least 3-4 days. It'll probably feel dry by the first day, but don't let this deceive you because it's not.

I also put it in an oven at 60°C for a few hours to even dry it better. I've had better results with this than letting it to dry for over a fortnight. I've heard of people using temperatures of about 100°C. It shouldn't ignite at these temperatures and even if it did, it wouldn't cause that much damage to your oven. I use simply 60°C just to be safe. Apply common sense. So, I wouldn't be using a gas oven.

There's nothing wrong with using KNO3 as the nitrate salt. He's a screenshot of ~1g of nitrocellulose I made with a distinct yellow flame from all the bicarb washes. It works just fine.

And yes, ensuring that you don't have an excess of cotton would help too. Here's the ratios I use that can be credited to Mumbles if you're interested:

H2SO4 - 60 mL
KNO3 - 36.30g
Cellulose (100% Cotton) - 5 g

With my last batch, I also added some excess sulfuric too towards the end to promote the nitronium ion being produced.



[Edited on 8-10-2010 by Bismuth]
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[*] posted on 8-10-2010 at 10:18


Quote:
Back to drying:

Allow it to dry. It will take at least 3-4 days. It'll probably feel dry by the first day, but don't let this deceive you because it's not.

I also put it in an oven at 60°C for a few hours to even dry it better. I've had better results with this than letting it to dry for over a fortnight. I've heard of people using temperatures of about 100°C. It shouldn't ignite at these temperatures and even if it did, it wouldn't cause that much damage to your oven. I use simply 60°C just to be safe. Apply common sense. So, I wouldn't be using a gas oven


I actually dry mine with those hot plates that can be more carefully regulated (not the "buffet" ones, those give off too much heat for this purpose.) I use pretty cheap ones I find in supermarkets around here, they are made by General Electric, they look sort of like this but with one burner:




In a few hours I have a sufficiently dry nitrocellulose that "flashes" very nicely. I even have successfully dried samples of nitrocellulose soaked in barium and strontium perchlorate solutions with such hot plates. The one soaked with the barium salt is pretty easily dried with little or no problem, and the combination seems very stable (I have a sample of it in a closed amber plastic vial; it's been there for several months now, and I have noticed no sign of deterioration.) The more hygroscopic strontium perchlorate requires more patience and skill to dry without it igniting, plus the mixture does not seem as stable as that of the barium salt (a sample of it closed in an amber plastic vial started to smell like chlorine after a few days of storage. It was disposed of immediately.) Nitrocellulose thus treated with barium and strontium perchlorate burns with a beautiful green and red-purplish flash, respectively.


[Edited on 8-10-2010 by Blasty]
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[*] posted on 12-12-2014 at 03:06


Hi All,

sorry to activate this old thread but my question is related to the same process.
I read this patent : Link
The patent talk about producing a nitrate solution using nitrate salt and high concentrated H2SO4

I followed the same steps for preparing NC. I used ammonium nitrate and 98% H2SO4.

this is a link for my NC : Youtube
the first one i burned was cotton and it gives very small residue.
the second sample was for my nitrated cellulose , it gave a spark but a lot of residue and this was not my expectations

I dried the NC well for 3 days in air path !

any idea about why my NC looks like this ?


[Edited on 12-12-2014 by ecos]
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[*] posted on 12-12-2014 at 04:01


I use 150ml cc. H2SO4,68g KNO3 and 6g of cotton.If you want really good you need to let it nitrate for 16-20 h.I see your pic,the cotton must be soak the nitrating mix completely.
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[*] posted on 12-12-2014 at 04:16


Quote: Originally posted by kecskesajt  
I use 150ml cc. H2SO4,68g KNO3 and 6g of cotton.If you want really good you need to let it nitrate for 16-20 h.I see your pic,the cotton must be soak the nitrating mix completely.

16-20h ?! WOW , too much time.
i only left it for 1 hour.
I think this is the reaction for the nitration solution:
H2SO4 + 2 NH4NO3 = 2 HNO3 + (NH4)2SO4
I can see nitric acid formed in solution.
so why we need more time when we use nitrate salt vs. Nitric acid?
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[*] posted on 12-12-2014 at 18:03


NB: the ice is no longer needed after the acid mixture is complete. Indeed you could let it cool and then nitrate the cotton at room temp. As mentioned above let it site overnight at the very least. You don't want decomposition of the cotton but you do want thorough nitration and that takes awhile. Cotton is not the same as glycerin. I've only used HNO3 for the mixtures but NaNO3 might work too. I read that somewhere.



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[*] posted on 13-12-2014 at 05:36
Nitrocellulose as propellant


Hi All,

I am trying to use NC as propellant for a small rocket.

I found some topics talking about NC as propellant : demonstration for NC

I prepared some poor NC : http://youtu.be/6O60mtRotf8

I will try to fix the problems I did in NC nitration since I used AN salt and I didnt give it enough time for nitration.

I prepared a plastic tube and compressed my NC inside it. I closed one terminal with compressed clay and duct tape.

it didn't work at all :( , i have some reasons for that but not sure.
1- Maybe the NC quality was very bad
2- I didn't add enough NC since the tube was narrow.

video for my trial : http://youtu.be/128a8Ybjb5M

Thx in advance
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[*] posted on 13-12-2014 at 06:25


What concentrations did you use for the synthesis? you need both concentrated HNO3 and H2SO4 to make a good batch.
You might be able to shoot away your rocket with NC using it as an explosive but as a fuel I think it would not work unless you find some way to make it decompose slower. :D have fun
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[*] posted on 13-12-2014 at 08:48


Quote: Originally posted by ecos  
Quote: Originally posted by kecskesajt  
I use 150ml cc. H2SO4,68g KNO3 and 6g of cotton.If you want really good you need to let it nitrate for 16-20 h.I see your pic,the cotton must be soak the nitrating mix completely.

16-20h ?! WOW , too much time.
i only left it for 1 hour.
I think this is the reaction for the nitration solution:
H2SO4 + 2 NH4NO3 = 2 HNO3 + (NH4)2SO4
I can see nitric acid formed in solution.
so why we need more time when we use nitrate salt vs. Nitric acid?


I get better yields and get very fast,almost as TMDD.I dont know why it need longer nitration in the salt method.
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[*] posted on 19-12-2014 at 02:10
NC as propellent


I made many search to find a stable mixture to be used as propellant for NC.

reference : Preparatory-Manual-of-Black-Powder-and-Pyrotechnics -- first edition
page 88

the mixture :



would wheat starch work instead of corn ? what is the 0.10% residue ?

did anyone have experience with such mixture or different NC mixtures?




[Edited on 19-12-2014 by ecos]
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[*] posted on 24-12-2014 at 11:32


Wheat starch could work but the wondra starch made from wheat seems a bit easier to stir together. I'd guess the residue is what remains from burning and they are just taking accurate account of energy. Look up ballistic modifiers.
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[*] posted on 28-12-2014 at 01:34
propellant


0,1% maybe acetone from procedure. For the function of propellant it is of little importance. But there is an important qestion. What is the purpose of all this effort? Art produce NC propelant ? Or manufactured rocket motor?
Experience is. This composition is excellent explosive. Low water absorption, good performance. VoD about 3000 m / s in dia. 15 mm. With 5% aluminium 3500mps. For rocket engines are used (in amateur practice) mixture of KNO3 65% and 35% sorbitol. NC based or high volume NC fuel engines is very expensive. Nobody used...:cool:...LL
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[*] posted on 28-12-2014 at 06:55


Yes,I think 0.1% is from acetone.

I have problem in synthesis of KNO3 or KClO3.
i used KOH + NH4NO3 to get KNO3 but ammonia gas was killing me and the reaction never ends.
i will try electroanslysis for KClO3 but the platinum plate or MMO are expensive.

I think NC is very powerful as propellent. I am interested to prepare a grain for testing purpose.

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[*] posted on 28-12-2014 at 12:30


If you found it hard to prepare Potassium nitrate, you will find it very much more difficult to prepare a reliable nitrocellulose based propellant, in my estimation.

If you have ammonium nitrate already, it is capable of being used for propellant purposes.


See Richard Nakka's experimental rocketry web site-

http://www.nakka-rocketry.net/anexp.html


Quote:

Other Experimenters Work:

Chuck Lauritzen has been working on ammonium nitrate propellants since February 2009 and reports lots of success with 38 mm motors. These propellants are based on A24 formulation but are modified with the addition of small amounts of ammonium dichromate (catalyst) and/or zinc dust, to ease ignition. Last spring Chuck launched a 4 lb. (1.8 kg) rocket to an altitude of 3,132 ft. (955 m.) with a 5 grain BATES configuration, using his own design with aluminum nozzles with graphite throat inserts and reports great success. Recently Chuck flew a single deployment 3.5 lb. (1.6 kg) rocket with a 6 grain motor that had 222 g. of propellant. Chuck reports "It looked like a speck in the sky at apogee and the upper winds carried it over a mile into a bean field.'



image.jpg - 114kB




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[*] posted on 28-12-2014 at 17:39


Quote: Originally posted by ecos  
Yes,I think 0.1% is from acetone.

I have problem in synthesis of KNO3 or KClO3.
i used KOH + NH4NO3 to get KNO3 but ammonia gas was killing me and the reaction never ends.
i will try electroanslysis for KClO3 but the platinum plate or MMO are expensive.

I think NC is very powerful as propellent. I am interested to prepare a grain for testing purpose.



If you did the reaction in a closed vessel with a tube leading the ammonia gas into an iced water bottle chilled as cold as possible you should be able to catch the gas and make a fairly strong ammonia solution at the same time. I. Would put the ammonium nitrate in and and cap it with a cap that has two tubes. One tube into a small bottle that has another tube leading into the water. This will catch suckback and keep the ammonia solution from being sucked back into the RBF. The other lead gets slowly fed with KOH in solution. This will keep some of the gas at bay and you get another useful chemical as well as the potassium nitrate you want.




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[*] posted on 29-12-2014 at 01:52


Hi Neonpulse,

I was thinking about this setup but I think the ammonia gas reacts vigorously with water as indicated in this video : http://youtu.be/vgBe0fsPcjk


Hi Bert,

I synthesized 6 grams of NC using ammonium nitrate salt and sulfuric acid , here is my test : http://youtu.be/5I_j2kUwMVo
I would be thankful if someone rate it.

i used 150ml H2SO4, 68g AN and 6g cotton. The cotton remained 20 hours in the solution as indicated in above posts from some colleagues.

I don't have a problem in getting AN from cold packs or even fertilizers but it is not easy to get other stuff like boron or KNO3 from stores.

I am aware of Nakka project but I don't know how to get the binders he use like chloroprene,Neoprene,....





[Edited on 29-12-2014 by ecos]
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[*] posted on 7-2-2015 at 13:02


Quote: Originally posted by ecos  
I made many search to find a stable mixture to be used as propellant for NC.

reference : Preparatory-Manual-of-Black-Powder-and-Pyrotechnics -- first edition
page 88

the mixture :



would wheat starch work instead of corn ? what is the 0.10% residue ?

did anyone have experience with such mixture or different NC mixtures?




[Edited on 19-12-2014 by ecos]


regarding the mixture of NC+AN or Nakka's mixtures (AN+S+AL) , I want to make ignition system using acetone peroxide but i am afraid of explosion !
i am thinking to use 0.5 grams only!, any idea here?
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[*] posted on 7-2-2015 at 14:00


Do not use acetone peroxide for an igniter. Not at all- It will likely blow up your device, possibly without igniting the fuel. If the fuel grain is cracked by your igniter, the fuel will have more burning surface area than designed and likely will over pressurize and CATO.

Use something that makes a hot flame, and/or something that leaves hot molten dross. Not something normally used to provide shock!

Elemental Boron and Potassium nitrate is a good high temperature gas/flame igniter.

Elemental Silicon and Potassium nitrate will also burn hot, and leave white hot glass slag stuck to the surrounding areas, which will continue to transfer heat to a pyrotechnic fuel for a good long time-

Black Copper oxide/Aluminum thermite is a popular igniter for high power rocketry amateurs as well-

Go read up on ignition systems and mixtures in Tenney Davis COPAE book found in sciencemadness.org library-

http://library.sciencemadness.org/library/books/the_chemistr...


[Edited on 7-2-2015 by Bert]




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2. List any points of agreement (especially if they are not matters of general or widespread agreement).
3. Mention anything you have learned from your target.
4. Only then are you permitted to say so much as a word of rebuttal or criticism.

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