Sciencemadness Discussion Board - Urea

Urea

Hey Buddy - 3-1-2021 at 20:39

Urea- there's a lot there. It's hard to keep track of the possibilities. Are the auto-condensation products of urea beyond biuret explored in energetics? Biuret is found. I can find very little on triuret, tetrauret and pentauret. Everything found seems unsubstantiated or unrelated to EM. Ie. from agriculture patents, (which is interesting in itself), but other than DNB, there seems very little.

Is there any exploration of the later condensation forms of urea in energetics?

; err I mean, whatchu think?

[Edited on 4-1-2021 by Hey Buddy]

Hey Buddy - 3-1-2021 at 20:58

Should ammonia be liberated out of this bitch or what?

j_sum1 - 3-1-2021 at 21:00

An awful lot would depend on what you were trying to accomplish.

Hey Buddy - 3-1-2021 at 21:08

Great, maybe somebody in beginnings will know about tetra and pentauret?

macckone - 3-1-2021 at 23:35

You get isocyanuric acid and ammeline.
This is how isocyanuric acid is made commercially.
You can also get various other azines and tetrazole compounds as low level contaminants.

https://en.wikipedia.org/wiki/Cyanuric_acid
https://en.wikipedia.org/wiki/Ammeline

Fyndium - 4-1-2021 at 00:31

Quote: Originally posted by j_sum1

An awful lot would depend on what you were trying to accomplish.

Truly, apart from ammonia generation, hydrazine and urea nitrate, are there any collection of useful purposes for urea?

j_sum1 - 4-1-2021 at 02:37

Quote: Originally posted by Hey Buddy

Great, maybe somebody in beginnings will know about tetra and pentauret?

For the record, threads of a general nature that open without a citation more properly belong in beginnings. It does not change the readership. But it does change the organisation of topics.

Boffis - 4-1-2021 at 03:35

@Hey Buddy; urea is a very useful compound in terms of being a starting material. Apart from buiret, isocyanuric acid an ammeline which are simply polymeric degradation products you can also derivatize it eg -> urea nitrate -> nitrourea -> semicarbazide -> whole world of semicarbazones and heterocyclics. Aliphatic amine + urea -> substituted ureas.

It can be used to prepare aromatic amines eg.; 4-nitrobromobenzene + urea = 4-nitroaniline; 2,4-dinitrochlorobenzene + urea; 2,4dinitroaniline and the related reaction picric acid + urea = picramide (2,4,6-trinitroaniline)

Alkalis + dry urea give cyanamides or cyanate depending on conditions.

From biuret via nitrobiuret to aminobiuret (actually a hydrazine derivative) to tetrauret

I have prepared buiret many times and I can tell you that none of the simple heating methods work very well. The two best methods unfortunately are very amateur unfriendly!! (one is via thionyl chloride and the other via direct chlorination of molten urea give yields >60%).

Aqueous lime water gives ammonia, Hoffmann's degradation give hydrazine etc. There is an entire monograph dedicated to the chemistry of urea.

If you want more specific help you will need to be a bit more specific on what you are trying to achieve. For instance are you simply trying to find some interesting /useful chemistry for it because you have a lot of it?

artemov - 4-1-2021 at 04:24

Quick aside.

For the recrystallization/purification of urea, can water be used instead of ethanol/methanol?
The solubility curve of urea in water seems quite advantageous too ...

njl - 4-1-2021 at 05:52

Yes, boiling water can dissolve ~5 Kg/L while only ~.5 Kg/L will dissolve at 0 C.

edit: Urea is also great for electrolytic H2 production since it is extremely soluble in water and decomposes at ~.4 volts as opposed to water at ~1+ volts. As previously mentioned, it can be used to make cyanamides (heterocycle precursors, dehydrating agents, bases etc.) and isocyanates (also heterocycle precursors and versatile reagents for the preparation of amines, carbamates, amides, carboxylic acids etc.). It is in my opinion one of the most versatile and valuable reagents to the amateur since it can find so many uses at a very low cost.

[Edited on 1-4-2021 by njl]

macckone - 4-1-2021 at 09:02

artemov,

You need to compare the impurity and the desired chemical curves.
In the case of urea, the primary impurity is usually biuret which is more soluble and has a flatter curve in alcohols.
If you are purifying fertilizer the urea is often mixed with ammonium sulfate which is much less soluble in alcohol so it can be crashed out of a water solution.

Ps. have you ever tried to pour or filter a saturated solution of urea in water?
Very viscous.

[Edited on 4-1-2021 by macckone]

artemov - 4-1-2021 at 19:57

Thank njl and macckone.

Quote: Originally posted by macckone

If you are purifying fertilizer the urea is often mixed with ammonium sulfate which is much less soluble in alcohol so it can be crashed out of a water solution.
[Edited on 4-1-2021 by macckone]

I dun really understand this part. Ammonium sulfate is much less soluble in alcohol, but it can be crashed out of a water solution?

Hey Buddy - 8-1-2021 at 11:51

Quote: Originally posted by j_sum1

Quote: Originally posted by Hey Buddy

Great, maybe somebody in beginnings will know about tetra and pentauret?

For the record, threads of a general nature that open without a citation more properly belong in beginnings. It does not change the readership. But it does change the organisation of topics.

Thanks for mentioning this. I thought I was being taken out backdoor by the ear, maybe I peed on a rug or something.

Hey Buddy - 8-1-2021 at 15:06

Quote: Originally posted by Boffis

@Hey Buddy; urea is a very useful compound in terms of being a starting material. Apart from buiret, isocyanuric acid an ammeline which are simply polymeric degradation products you can also derivatize it eg -> urea nitrate -> nitrourea -> semicarbazide -> whole world of semicarbazones and heterocyclics. Aliphatic amine + urea -> substituted ureas.

It can be used to prepare aromatic amines eg.; 4-nitrobromobenzene + urea = 4-nitroaniline; 2,4-dinitrochlorobenzene + urea; 2,4dinitroaniline and the related reaction picric acid + urea = picramide (2,4,6-trinitroaniline)

Alkalis + dry urea give cyanamides or cyanate depending on conditions.

From biuret via nitrobiuret to aminobiuret (actually a hydrazine derivative) to tetrauret

I have prepared buiret many times and I can tell you that none of the simple heating methods work very well. The two best methods unfortunately are very amateur unfriendly!! (one is via thionyl chloride and the other via direct chlorination of molten urea give yields >60%).

Aqueous lime water gives ammonia, Hoffmann's degradation give hydrazine etc. There is an entire monograph dedicated to the chemistry of urea.

If you want more specific help you will need to be a bit more specific on what you are trying to achieve. For instance are you simply trying to find some interesting /useful chemistry for it because you have a lot of it?

This is what I've come to understand. And correct me with anything I'm not understanding; That urea is both a simple molecule and a functional group(?). Massive exponential spread of possible extensions in step series. > GN, DPT, Hydrazine, semicarbazide, carbohydrazone, NH3, etc.

In terms of energetics, upon heating under specific conditions,, a series of condensation transformations occur. The transition is not a linear progression by temp, but by a heating and pressure/oxygen matter. Have the macromolecules been explored? I can't find anything.

Attachment: US3453098.pdf (529kB)
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It's all quiet now. Maybe I've asked something stupid?
Is there any reason not to nitrate or perchlorate the higher condensation products or macomolecules in general? I'm totally unfamiliar with this, and chemistry in general, so I don't know if this is a silly question. Any help?

[Edited on 9-1-2021 by Hey Buddy]

Hey Buddy - 14-1-2021 at 06:43

Update: I've found energetic research on melamine, ammeline, and cyuranic. Of course biuret is already widely explored..
Have still not located any research on triuret tetrauret or pentauret, which are all condensation products. If anyone is aware of research on energetic compounds of those please respond.
Have located patents on isolation processes for triuret but nothing on tetrauret nor penta. If anyone knows a process to isolate those please respond.
Id like to experiment with urea beginning with the lesser explored areas first, thank you.

[Edited on 14-1-2021 by Hey Buddy]

B(a)P - 14-1-2021 at 12:27

In Boffis' post above they describe the route to isolate tetrauret.
There is more information in here, also provided by Boffis under another thread.
Very interesting stuff!
http://www.sciencemadness.org/talk/files.php?pid=613206&...

Hey Buddy - 15-1-2021 at 17:40

Excellent, thank you. --Two documents I've found of interest are a 1950s procedure of melamine and other products by simple heating in pipes at various densities and Temps. The second is experimental tetrauret macrocycles. Really a dizzying array of possibilities with urea. It's plastic derivatives are fascinating too. Apparently urea products can be used for desensitization coating of classics like RDX.

Attachment: Melamine from Urea.pdf (1.8MB)
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Attachment: Tetraurea.pdf (2.7MB)
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[Edited on 16-1-2021 by Hey Buddy]

Hey Buddy - 16-1-2021 at 22:57

The urea likes to recrystalyze

Hey Buddy - 26-1-2021 at 06:22

Update: Have worked up through biuret to melamine.
Experimenting now with gCN/BgCN. Biuret is very easy in isolation, as it's the first condensation, limited to temp ceiling 189C. Biuret conversion appears reasonsbly possible in open vessels. Triuret, tetrauret, pentauret, cyuranic, ammelene, ammelide, are much more difficult in discrimination. The isolation of these by thermal condensation without gas feed is not well understood. building some vessels for pyrolytic condensation and gas feed now.

Currently in digressions of gCN. Sort of necessary pit stops on the way to EMs. Its watersplitting ability in solar applications and the gCN catalytic abilities, which seem pretty incredible. Within this there is microwave production of melem using KNO3 as an exfoliator. Urea and KNO3 mixes produce high surface area gCN for cats. But I'm interested in its effect on homogenous formation of melamine enroute to melem.

The most significant condensation of urea where EM is concerned, (imo) is melem/melon. The production of gCN passes through the stages of melamine and then melem prior to being calcinated into gCN.

Melem is a heptazine from urea. Melon appears to be an autocondensed poly lattice of melem. Energetic heptazines and be made from melem. It is pretty unexplored for the most part. A lot of theoretical compounds. I've read the claim that n-oxide impinged heptazines are theorized to have impact and thermal sensitivity from the range of TNT all the way up to RDX with several of the compounds having greater vod than cl20. Most of the theoretical compounds have greater vod than HMX and with less sensitivity. This is the reason i am interested in Urea. Its products are a vast library and in this area it can be purchased bulk by anyone at $316/Ton.

Will continue to explore and post useful findings. see attachments on heptazines.

I dont schpreken ze Deutsch is anyone would like to help explain that 2nd one i would love to know more. Thank you.

Attachment: Heptazine n-oxide high performance.pdf (1.5MB)
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Attachment: Deutsch _hepta.pdf (474kB)
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[Edited on 26-1-2021 by Hey Buddy]

[Edited on 26-1-2021 by Hey Buddy]

njl - 26-1-2021 at 07:51

Forgive my ignorance but is gCN/BgCN cyanoguanidine and cyanobiguanidine (correct nomenclature aside)? When you say "kno3 and urea produce high surface area for cats", do you mean for catalysis?

rockyit98 - 26-1-2021 at 08:15

Making Graphitic carbon nitride (g-C3N4) from urea
https://www.sciencemadness.org/whisper/viewthread.php?tid=154866#pid631050

Hey Buddy - 26-1-2021 at 08:40

Quote: Originally posted by njl

Forgive my ignorance but is gCN/BgCN cyanoguanidine and cyanobiguanidine (correct nomenclature aside)? When you say "kno3 and urea produce high surface area for cats", do you mean for catalysis?

My apologies, "gCxNx" is the way graphitic carbon nitride is described in energy study literature. BgCN is boron graphene carbon nitride. "Cat" im just contracting "catalyst".

Here is some info on KNO3/Urea catalysts look under "CNU-30":

Attachment: Microwave melamine carbon nitride.pdf (6.9MB)
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Hey Buddy - 26-1-2021 at 09:05

See what I'm talkin about?

Urea.

It's where it's at.

Urea covers everything from low order det to fastest and everything between.

Attachment: Polyazine.pdf (791kB)
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RustyShackleford - 26-1-2021 at 09:17

Quote: Originally posted by Hey Buddy

Biuret conversion appears reasonsbly possible in open vessels.

Very much is, i did it in a 500ml beaker with a RBF on top. worked perfectly fine. The isolation of the biuret is easier with beaker also, just add dilute hydroxide (2-3% or so, as long as it stays above 9-10) , heat till dissolved, cool and collect crystals, then rex it from distilled water to rid the last trace of hydroxide.

macckone - 26-1-2021 at 15:32

artemov,
Crashing out of water using alcohol as a cosolvent is useful for a number of purifications.
The basic procedure is to dissolve a urea/ammonium sulfate mixture in minimal water.
Then add about 4 times as much dry alcohol as solution.
The ammonium sulfate will form fine crystals free from urea.

Ammonium sulfate is only slightly soluble in 80% alcohol while urea is very soluble.

The procedure I actually use involves dissolving it in significantly more water than necessary and evaporating most of it off, then adding alcohol.

Since the stuff I get is fertilizer grade, I can filter off insoluble impurities with the excess water.
Then get nice pure crystals that I can rinse with alcohol to get rid of any remaining urea.

The alcohol can be redistilled and reused.
The remaining urea can be recrystalized from dry alcohol.

The mix I get is about 90% ammonium sulfate and 10% urea.

artemov - 27-1-2021 at 03:33

Quote: Originally posted by macckone

artemov,
Crashing out of water using alcohol as a cosolvent is useful for a number of purifications.
The basic procedure is to dissolve a urea/ammonium sulfate mixture in minimal water.
Then add about 4 times as much dry alcohol as solution.
The ammonium sulfate will form fine crystals free from urea.

Ammonium sulfate is only slightly soluble in 80% alcohol while urea is very soluble.

The procedure I actually use involves dissolving it in significantly more water than necessary and evaporating most of it off, then adding alcohol.

Since the stuff I get is fertilizer grade, I can filter off insoluble impurities with the excess water.
Then get nice pure crystals that I can rinse with alcohol to get rid of any remaining urea.

The alcohol can be redistilled and reused.
The remaining urea can be recrystalized from dry alcohol.

The mix I get is about 90% ammonium sulfate and 10% urea.

Oooooo ... thanks!

Hey Buddy - 3-3-2021 at 14:48

I've isolated melamine and some lesser condensed ureas. I'm enroute to s heptazines but I'm slow. Intent now is to experiment with oxidation of melamine prior to moving on to melem and melon. For those intent is oxidation and then complexing with metals and nitroso complex. For now melamine. MDO is 2,4,6-triamino-1,3,5-triazine-1,3-dioxide. It has a meager det rate but is a good starting point enroute to MDONA. In reference to RSC Adv., 2021, 11, 288–295 | 289, they are using hydrogen peroxide/TFA for oxidation. Is there an equivalent of TFA that is less expensive? I have read that melamine adducts readily with many things including both H2SO4 and H2O2. Does it make any sense to attempt oxidation with Melamine/h2o2, urea/h202? Or is there an alternative? Ozonolysis in solvent? I'd rather avoid TFA.

[Edited on 3-3-2021 by Hey Buddy]

Attachment: d0ra09105g (1).pdf (670kB)
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^MDO/MDONA/MDOP

[Edited on 3-3-2021 by Hey Buddy]

draculic acid69 - 4-3-2021 at 00:30

Quote: Originally posted by Fyndium

Quote: Originally posted by j_sum1

An awful lot would depend on what you were trying to accomplish.

Truly, apart from ammonia generation, hydrazine and urea nitrate, are there any collection of useful purposes for urea?

Alkali Cyanate production and therefore cyanide

Fyndium - 4-3-2021 at 03:02

That obvious one, of course, which I have done already with success.

Other one is urea hydrogen peroxide adduct, which can come in handy. I was thinkering could it be extracted from sodium percarbonate, but the solubilities limit the recovery. Possibly using a solvent that dissolves urea and hydrogen peroxide but not sodium carbonate either as is or by adding it to water solution to crash out the carbonate?

Hey Buddy - 6-3-2021 at 19:17

Quote: Originally posted by draculic acid69

Quote: Originally posted by Fyndium

Quote: Originally posted by j_sum1

An awful lot would depend on what you were trying to accomplish.

Truly, apart from ammonia generation, hydrazine and urea nitrate, are there any collection of useful purposes for urea?

Alkali Cyanate production and therefore cyanide

I'm not even any good at chemistry and I can clearly see that urea is significant. I've been reading of it's application in industries and chemistry for about 4 months now and there is no end in sight. It is wonderful. In energetics, I view it as a tree diagram, with incredible fractals of potential. The condensation products alone are each fascinating with wide and diverse application. Urea can be used directly as a fertilizer, biuret on the other hand inhibits plant function until it decomps into urea, where it then becomes a fertilizer. It continues on like this. Melmine and melem, melon are really exciting because there is relatively little exploration in that area, its recent interest is due to carbon nitride and boron nitrides, which are easily produced from melemine. Melamine is incredible and is clearly underutilized. For instance melamine forms an adduct with both H2SO4 and HNO3. They are relatively safe and very stabile solid reagents with can be used in reactions without solvent using mechanical and pneumatic low pressure mixing or ultrasonic mixing. Melamine can be used in the latter half of CL-20 synthesis. Melamine forms adducts very easily with hydrogen bonding with acids cyanuric and complexes with boric acid. Melamines conversion to carbon nitride can be used in photocatalytic production of hydrogen or hydrogen peroxide using sun light as the only energy source. Melaminium sourced CN can be used as catalysts and early forms (prior to 1800c heating) of melaminium derived BN can act as modifiers in the energetic profiles of propellants and explosives, dramatically altering their behavior in decomposition. That's not even getting into the polymer and adhesive applications. Melamine can be used in desensitization of explosives as well. They make LEDs in the blue light spectrum from melem directly and a salad bar of other supramolecular creations and complexes. And that's only a slice of its pie. Guanidium branches from urea are even more dizzying. It is absolutely incredible and is in tremendous critical usage and production world wide. To read someone suggest it's uses are limited is baffling. I must disagree, it is useful.

The other aspects of urea which make it interesting are its high volume consumption globally, which makes it absolutely critical. It is not like ammonium nitrate which can be supplemented, urea cannot be supplemented. But even if it were to be regulated out of circulation, which is not possible, it can be easily produced. The urea production patents should be reproducible using a couple of exhaust manifolds and exhaust pipes from a junk yard and a welder. But that's only necessary if it's of novel interest because the guy down the road sells urea @$300/ton. I asked him. He said he will dump directly into any container, and can even fill truck beds as long as it's below a certain height from the top of the bed and reduced speeds are used to prevent urea contamination during transport.

[Edited on 7-3-2021 by Hey Buddy]