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Biuret ?

underground - 13-1-2014 at 01:03

I saw this chemical from wikipedia and it looks interesting for nitration! Has anybody play with that ever ? It may have some good properties as an EM, Maybe some di/trinitrobiuret or whatever...

[Edited on 13-1-2014 by underground]

Dany - 13-1-2014 at 01:58

take a look on this PhD thesis (2005):

PhD thesis

search in the Pdf for biuret.

Dany.

underground - 13-1-2014 at 02:11

The link does not work for me. I can not open the pdf file

Dany - 13-1-2014 at 02:27

download from here:

http://www45.zippyshare.com/v/34298528/file.html

Dany.

underground - 13-1-2014 at 03:18

Firstly a big thanks to Dany, a really good pdf file!

By the way,we have some good points here. Dinitrobiuret it looks like a little bit sensitive EM, i guess something close to ETN, but it looks stable in air, i guess it will be also stable in storge, with positive OB and with VoD of 8660, almost as RDX. The positive OB may also help to further increase the VoD with some addition fuel. Also, some salts can be formed. I bet that the ammonium salt of Dinitrobiuret shoud have a really high VoD !! Or even better the guanidine salt of Dinitrobiuret!!

[Edited on 13-1-2014 by underground]

DubaiAmateurRocketry - 13-1-2014 at 04:23

Biuret have a very high negative heat of formation, therefore its less advantages compared to some other similar compounds such as guanidine and carbohydrazide however, i believe biuret is more dense, and it can probably form salts such as biuret dinitrate.

underground - 13-1-2014 at 06:58

I bet biuret will form more stable and storage salts than those of guanidine and urea, a really big advantage...

[Edited on 13-1-2014 by underground]

DubaiAmateurRocketry - 13-1-2014 at 10:10

Dinitrobiuret seems like it does not have a high impact sensitivity. some links for more info on DNB

https://www.google.ae/url?sa=t&rct=j&q=&esrc=s&a...

http://www.dtic.mil/dtic/tr/fulltext/u2/a547366.pdf

I still wonder if nitro-guanidine cation exist.

http://www.chemspider.com/Chemical-Structure.16372117.html

such as one stated in this picture, it have similar OB with dinitrobiuret however it should be more energetic since the C=O group on dinitrobiuret causes high negative hof.

VladimirLem - 13-1-2014 at 10:58

Quote: Originally posted by DubaiAmateurRocketry

Dinitrobiuret seems like it does not have a high impact sensitivity. some links for more info on DNB

https://www.google.ae/url?sa=t&rct=j&q=&esrc=s&a...

sweet....very interesting stuff

but how to make the MonoNitro-compound?
simple synthesis with, lets say, 65% HNO3 ?

8660m/s and 33.9GPa sounds preety interesting...
they wrote that the performace of it will be between PETN and HMX !!

underground - 13-1-2014 at 13:06

Also how biuret can be formed from urea ? and how can we separate it ?

Update:
Biuret It is formed during urea production upon heating urea at 80 Degree C and higher, especially above its melting point according due to the following reaction release of ammonia:

2 CO(NH2)2 → H2N-CO-NH-CO-NH2 + NH3

[Edited on 13-1-2014 by underground]

DubaiAmateurRocketry - 14-1-2014 at 07:06

Umm.. I also think diamino guanidine, triamino guanidine, carbohydrazide competitive.

Elemental analysis of diamino guanidine compared to guanidine shows spectacular differences in its nitrogen content.

Diamino guanidine H2NNHC(NH)NHNH2, 13.5% Carbon, 78.6% Nitrogen, 7.9% Hydrogen,

Guanidine, CH5N3, 20.3% Carbon, 71.1% Nitrogen, 8.53% Hydrogen.

Carbohydrazide, CH6N4O, 13.3%Carbon, 6.7% Hydrogen, 62.2% Nitrogen, 17.7% Oxygen.

Biuret C2H5N3O2, 23.35%Carbon, 41% Nitrogen, 4.9% Hydrogen, 31% Oxygen

Urea, CH4N2O, 20% Carbon, 6.7% Hydrogen, 46.6% Nitrogen, 26.6% Oxygen.

Biuret has lowest nitrogen/highest carbon content with lowest heat of formation which is unfavorable to be used in EM which is most likely why its less investigated, I am interested in carbohydrazide and diamino guanidine salts. They both can form 2+ cation. Diamino guanidine dinitrate [CH8N4O]2+ 2[NO3]- (CH8N6O7) might have a good VoD.

Triamino guanidine nitrate (this mono nitrate version is not good)
http://www.explosia.cz/en/vupch/download/tagn.pdf

Dinitrate salts of above triamino, diamino, amino guanidine, and some others are mentioned in this patent. I still look forward to the didinitramide version
http://www.google.nl/patents/CA2342366A1?cl=en

Also wonder if Urea dinitramide is ever synthesized.

[Edited on 14-1-2014 by DubaiAmateurRocketry]

underground - 15-1-2014 at 07:49

Also there is triuret out there.... What about triuret dinitrate ?

And one more think, how can i form different tipes of salts with dinitrobiuret as an cation, like ammonium dinitrobiuret ?

[Edited on 15-1-2014 by underground]

Motherload - 2-2-2014 at 19:59

I was thinking .... How Di Nitro Urea is used in Keto-RDX synth ....
What impact would it have if it was to be replaced by Di Nitro Biuret ??
Keto-HMX perhaps ?

DubaiAmateurRocketry - 3-2-2014 at 05:03

Quote: Originally posted by Motherload

I was thinking .... How Di Nitro Urea is used in Keto-RDX synth ....
What impact would it have if it was to be replaced by Di Nitro Biuret ??
Keto-HMX perhaps ?

maybe not exactly what you want to see, and not same structure with HMX, however this is also 8 membered fused ringed compound has 2 dinitrourea group(which include 2 keto and 4 NNO2, similar to that of HMX)

http://www.iloveexplosives.com/2008/10/sorguyl-aka-tgnu-synt...

underground - 5-2-2014 at 03:24

Here is a copy - paste message from a very good friend on this forum

From urea, biuret is obtainable via heating at a specific temperature (a little search in freepatents online should give you some hints...presence of biuret is observable because of the specific coloration it displays with copper salts complexation...the solution turns from the usual blue to pink-violet. Maybe there is an isolation process playing on that property; or fractionnal cristalization.
Once you have biuret...with diluted HNO3 you would get biuret dinitrate...allow to evaporate until dry and cristaline and finaly treat the dinitrate with >98% H2SO4 (like the system to make nitroguanidine from guanidine nitrate -or- nitrourea from urea nitrate) to get the dinitrobiuret.
The investigation of the salts of DNBiuret might lead to discovery of new primaries or propellants!
O2N-N(Z)-CO-NH-CO-N(Z)-NO2
Z being a metal (Na,K, Pb, Cu, Ag, Hg, ...)or an amine (NH4, N2H5, NH3OH)...

Motherload - 5-2-2014 at 08:42

Are you sure one would get Di nitrate and not just nitrate in one step via dil HNO3 ?

underground - 5-2-2014 at 10:19

Quote: Originally posted by Motherload

Are you sure one would get Di nitrate and not just nitrate in one step via dil HNO3 ?

This is a message from an another member on this forum... he told me that and then i just copy-paste the message

Also i was thinking for something else, biuret has more oxygen and nitrogen content and it is denser than guanidine. Also aminonitroguanidine nitrate has a VoD 9750m/s calculated but unfortunately it is not so storage stable e.t.c. Ammonium Dinitroguanidine has a VoD 9055m/s calculated. So i was thinking for aminonitrobiuret nitrate and Ammonium Dinitrobiuret not only because their VoD i guess would be greater, but also for their chemical and storage stability.

[Edited on 5-2-2014 by underground]

VladimirLem - 5-2-2014 at 11:07

Quote: Originally posted by Motherload

Are you sure one would get Di nitrate and not just nitrate in one step via dil HNO3 ?

i read alot about DNB last month and im pretty sure, that when taking diluted HNO3 at the first step, you get the mono-nitro compound....

i never read about (di)nitrate stuff when reacting biuret with HNO3

[Edited on 5-2-2014 by VladimirLem]

underground - 5-2-2014 at 14:58

Quote: Originally posted by VladimirLem

Can you share with us your sources about Dinitrobiuret ?

VladimirLem - 6-2-2014 at 10:55

Quote: Originally posted by underground

Quote: Originally posted by VladimirLem

Can you share with us your sources about Dinitrobiuret ?

i searched the shit out of google and only found a few PDFs...

"High energy density materials based on tetrazole and nitramine compounds"
"Dinitrobiuret & its Salts"
"thermal decomposition of 1,5-DiNitroBiuret"

there are very rare informations out there :/ the VoD and performace seems pretty interesting...but no sources about exact density.
Solublity (Mono, Nitro) is anywhere in the PDFs.
DNB seems to be chemical instable to alkaline compounds.

i also found a source that said, making biuret out of urea will be a damn long and inefficient process (heating for days at the decomposition themerature of urea) so i dounbt i will ever make it and carry on with electroforming copper-lines for shaped charges (and testing some easier to make explosives of course^^)

underground - 7-2-2014 at 02:43

I though that biuret could easily be made out of urea,this thing change everything.

VladimirLem - 7-2-2014 at 07:49

Quote: Originally posted by underground

I though that biuret could easily be made out of urea,this thing change everything.

well...this source says something about a few hours, but the yield seems to be not really good...

http://link.springer.com/article/10.1007%2Fs11814-009-0164-0...

the advantage is, that it seems to be very easy to wash the urea/biuret mixture with cold water and getting 95%< biuret, cause urea is very soluble in water and biuret just a little bit

underground - 8-2-2014 at 05:53

Quote: Originally posted by VladimirLem

Those catalysts looks really dificult to find... Have you got any document about the temperature, the quantity of urea used, the time is needed and the final yelds of biuret ?

VladimirLem - 8-2-2014 at 08:45

Quote: Originally posted by underground

Those catalysts looks really dificult to find... Have you got any document about the temperature, the quantity of urea used, the time is needed and the final yelds of biuret ?

i didnt read the complete text...and by the way, i see this link doesnt work correct...when browsing from google, a pdf opens (images below)

underground - 9-2-2014 at 17:02

So it looks like the yelds are close to 22%, This is not so bad, urea is cheap and this reaction can be used with big quantities to get as much biuret as you like

PHILOU Zrealone - 22-2-2014 at 05:28

Out of PM with underground:
-QUOTE-
You should search in Freepatents Online or Google Patents...on the web.

There you can download pdfs files where there are a lot of informations.

I have searched a bit for you among a 30 number of patents about urea and biuret and I have found the most relevant to our case:

US4701555-Methods for removing biuret from urea by adsorption
US3184508A-Crystallization of biuret from biuret containing aqueous solutions saturated with urea
US3150177A-process for producing biuret
US2524049A-production of biuret
US2370065A-manufacture of biuret
US2145392A-preparation of biuret
-END OF QUOTE-

Based on those chosen patents and taking into account urea is cheap, the process is easy and separation between urea/biuret quite simple, even if biuret is formed in 20-40% of the theorical; urea is recoverable and so the process by reinjection/reuse of urea recollected/recrystallized could be set close to 90%.

My chemical point of view:
-Dinitrobiuret allows one to get the power of DNU with lower hydrolytical troubles.
-Density is highly enhanced what is good for brisance and VOD.
-Metalic salts of DNB are potential primaries, especially heavy metal salts.
-Most interesting amine salts would be di-hydroxylamonium, di-hydrazonium and di-ammonium.

Reaction of DNB with 1 equivalent of formaldehyde may form:

-A kind of diketo-RDX and methylene dinitramide related molecule (cyclo(-CH2-N(NO2)-CO-NH-CO-N(NO2)-)... this cyclic compound will be acidic owing to its NH entrapped between two CO and might thus also form interesting primaries metal salts and interesting energetic amine salts (hydroxylamine, hydrazine and ammonia).

-Also possible and more interesting a linear polymer (-CH2-N(NO2)-CO-NH-CO-N(NO2)-)n ... this will outperform any cyclic nitramine because any linear polymer tends to reach higher densities than monomer owing to increase of Van-der-Waals attraction forces; also linear polymers tends to have lower impact sensitivities. This polymer will also display acidic sites and might thus form also metallic primary salts and energetic amine salts.

-A second equivalent of formaldehyde may react on the acidic NH to form a methylol that is nitratable eather on the cyclic-monomer or on the linear polymer (-CH2-N(NO2)-CO-N(CH2ONO2)-CO-N(NO2)-)n.
This can also result in bridging of two diketo-RDX like cyclic monomers (cyclo(-CO-N(NO2)-CH2-N(NO2)-CO-N)-CH2-(cyclo(N-CO-N(NO2)-CH2-N(NO2)-CO-) a non-acidic/neutal molecule; or even better methylene bridging of various linear polymeric strands to make a non-acidic very high density thermo-hardening or a rubber like energetic plastic.

underground - 27-2-2014 at 02:36

How can the hydroxylamonium salt can be form ? I can not see anywere any source of hydroxylamonium carbonate/bicarbonate e.t.c.

di-hydroxylamonium dinitrobiuret looks very promising as long as it is going to have only slightly negative OB

Also biuret because it consist of 2 urea molecules together, i guess it will be as much easy to nitrate it to dinitrobiuret salt as much easy the nitrourea salt going to be.

[Edited on 27-2-2014 by underground]

DubaiAmateurRocketry - 28-2-2014 at 12:22

Potential EM from ANQ and NSC

Compounds like biuret, guanylurea, biguanide, and thereof gives less nitrogen content and more carbon. These types of compounds contain less hydrogen bonds and function units per mass than urea and guanidine have. Therefore, I think guanidine and urea and their derivatives have much more potential.

Many of you might already seen this, Thomas M. Klapotke synthesized 1-Amino-3-nitroguanidine nitrate. With perfect OB balance, its hydrogen bonds gives it safer impact sensitivity and higher density than HMX. Reaching a VoD of nearly 9600 m/s according to EXPLO5.04. DOI: 10.5560/ZNB.2012-0066

The paper's dinitramide salt is also promising, with a reported dehydration temperature of around 70 degree celsius, the impact sensitivity of the hydrated salt is around 10J. This compound have a CO OB balance of nearly +20% and seems like a promising oxidizer. The dehyrated compound should have over 1.9 density(the nitrate is already over 1.9, and dinitramide anion usually gives higher density) and the dehydrated salt probably a better impact sensitivity than ADN since there're hydrogen bonds and the ammonium cation does not.

dinitrourea can react with hydrazine to give 4-nitro-semicarbazide according to this paper. However it only gives moderate yeild around 50%. I think 4-nitro-semicarbazide can be synthesized directly from HNO3 and semicarbazide to give semicarbazide nitrate, and then treating it in sulfuric acid. However I did not find a paper saying that was possible. Another method could be hydrazinolysis of nitrourea, did not find any paper on this reaction either. Anyways, I guess 4-nitro-semicarbazide could be protonated by acids like HNO3, to form 4-nitro-semicarbazide nitrate, dinitramide, dinitrourea, dinitroguanidine etc.

[Edited on 28-2-2014 by DubaiAmateurRocketry]

Boffis - 26-4-2019 at 03:48

Has anyone ever actually tried to prepare biuret? I am in the process of trying out various method with wildly variable and erratic results. I could do with a bit of practical advice. I have tried the simple heating of urea alone (yield very poor <3%), with inorganic salts under reduced pressure (better results but not as good as the patent claims), with thionyl chloride (difficult to control reaction, excellant yield in a small scale trial but full-scale 100g or urea yield seems very poor). I also tried the urea salt + K cyanate and again got modest results. Details to follow in a few days.

MineMan - 28-4-2019 at 16:06

Look up tetrazolover

Boffis - 2-5-2019 at 13:56

@MineMan,

Look up tetrazolover

??

MineMan - 4-5-2019 at 14:33

Yup. He has a YouTube channel.

underground - 19-5-2019 at 02:11

After waching this video on youtube

https://www.google.com/url?sa=t&source=web&rct=j&...

i thought that i could try it the same on my own too

After about 2-3h of boiling urea, everything was solidified. Here is a photo of the stuff fully powderized

https://ibb.co/85xsL9y

I tried to react it with 65% NA. There was a rise in temp of 35oC and here is the result.

https://ibb.co/CvJXJSM

Here is urea nitrate in comparison

https://ibb.co/CQrm0Vh

Now i tried to nitrate some of this stuff with 200g SA 65g Kno3 and 25 of supposed biuret. During addition of supposed biuret there was a rise of temp. The wierd this is that there was some bubbling .

https://ibb.co/hZLh32N

I guess there was a decomposition. Max temp during nitration was 35oC. Now i got no yields after crashing in water. Before crashing the mix was a bit thick so i supposed that i got something. Anyway i dont know if i got no yields cause the temp was too high or because i just have not got any biuret at all. I may try again to nitrate it at lower temps or try to detonate the stuff reaced with 65% NA.

[Edited on 19-5-2019 by underground]

Laboratory of Liptakov - 19-5-2019 at 11:08

Edited from patent: US3150177A
Claim:
1. A process for the preparation of biuret from urea, said biuret being substantially free of cyanuric acid, which comprises heating urea at atmospheric pressure to about 140 Celsius. After form a melt, subjecting the heated melt to a reduced pressure of about 140 to 150 mm of mercury rod. (edit / normal athmospheric pressure is 760 mm of mercury rod ) Raising the temperature ( at reduced pressure) of said melt over a period of about a few minutes on150 to 160 Celsius. And simultaneously reducing the pressure to below about 75 mm of mercury rod. Result is stantially completely free of cyanuric acid and sodium cyanurate.

2. A process for the preparation of biuret from urea as set forth in claim 4 wherein said aqueous solution of sodium hydroxide contains about 2 to 3% dissolved NaOH.

3. A process for the preparation of biuret from urea as set forth in claim 4 wherein said aqueous sodium hydroxide solution containing said discharged reaction mass is heated to about to level, to facilitate solution of said reaction mass.

4. A process for the preparation of biuret as set forth in claim 1 wherein said urea is heated in the presence of a catalyst which is soluble in and does not form a precipitate with said aqueous alkali said catalyst being selected from the group consisting of disodium and boric acid.

........ :cool:

......It's time to determine the exact way to make pure Biuret from urea. But without applying reduced pressure...... :cool:

....LL

Solubility urea is 108g in 100g water at 20 C
Solubility biuret is 2g in 100g water at 25 C

Melting point urea....134 C....Melting point Biuret.....190 C...= decompose

Boffis - 20-5-2019 at 13:43

@Underground, nitration of biuret is recommended to be maintained at <0 C and also you have far to much KNO3. The reaction is nearly quantitative with a 1:1 ratio for the mononitro compound. For the dinitro compound the excess of nitrating agent should still be a small excess say 5% to avoid decomposition of the product.

Dr. Lipatkov. The problem I find with a lot of procedures is they are short on precise details. Separating biuret from urea or ammonium chloride is easy, it is maximizing the yield per unit of effort that is the problem since urea itself is cheap. The best yield I have achieved was using a procedure I found in a footnote to an old German paper. I translated it at the time and have it somewhere. Basically this procedure involved passing chlorine into molten ammonia at c 140 C (yield c 55% assuming 2urea = 1 biuret). I have also tried the molten urea + sodium hydrogen phosphate (or other salts) under reduced pressure to assist removal of the ammonia formed (11% with same assumption); the potassium cyanate + urea hydrochloride (8% of theory, much cyanuric acid)/nitrate (30%) and thionyl chloride on urea (50%). They all work but each has its own little problems. If you have access to thionyl chloride the last procedure is the simplest, if not the first is probably the next best but it has the problem of working with much chlorine. I have had only limited success with the straight heating of urea, never >20%. The patent that describes the various salt catalysed methods makes claims of 70% but I could not repeat these yields.

Laboratory of Liptakov - 20-5-2019 at 22:13

Thanks very much, Boffis. You do great research on this theme. I estimate, that I early leave the field of research on biuret theme. It seems, that pure Biuret (95%?) is impossible produced.... :cool:

...LL

Boffis - 21-5-2019 at 07:06

@Dr Liptakov, just incase you or someone else would like to try the Thiele & Uhlfelder "chlorine on urea" method I have attached my translation of their paper, see the footnote at the bottom of p95 (original page numbers). There is some interesting chemistry in this paper.

Attachment: On Biuret and aminobiuret JLAC Thiele & Ulhfelder 1898 English.pdf (151kB)
This file has been downloaded 481 times