R-Salt is an interesting substance. Its a relative of RDX. Its a nitrosoamine variant of RDX, wheras RDX is N-Nitro. Its also known as CTMTNA - Cyclotrimethylenetrinitrosamine. Its performance is similar to RDX, and it is less sensitive. However, it is incompatible with H2SO4 - it explodes on contact with conc H2SO4. It is possible to (oxidize?) it to RDX, however I prefer to use it as-is.
I have posted data gethered from SMDB on the subject, and posted a few .pdf's I originally got there.
Its preparation is VERY simple and OTC. It uses HCl, NaNO2 and Hexamine.
Hexamine can be prepared from formaldehyde and ammonium hydroxide, formaldehyde by oxidation of methanol. Ammonium hydroxide by making ammonia from NaOH and an ammonium salt (Ammonium Nitrate is best) and water, and by bubbling the ammonia through cold water. I say to use AN because it creates NaNO3 as a 'waste product' which can be then reduced to NaNO2 for the synth.
NaNO2 can be made from NaNO3 by reduction in melt with lead, or by other methods detailed on this board.
HCl can be made by adding table salt to H2SO4 and bubbling the HCl gas through cold water. Its easier to buy it OTC.
PROPERTIES OF R-SALT:
VoD 7300m/s at 1.5g/cc.
LB expansion 370cc.
Soluble in boiling alcohol, slightly in H2O.
At 1.57g/cc requires 2.5g Mercury fulminate, and VoD is 7800m/s.
Decomp w/ evolution of ammonia and formaldehyde on contact with NaOH.
Explodes on contact with conc. H2SO4.
SYNTHISES of R-SALT:
7g Hexamine is dissolved in 50ml water. Mix with 400g ice in beaker. Add 26ml conc HCl.
Dissolve 10.4g NaNO2 in 50ml water, pour into beaker with ice.
Let soln. stand a hour.
Filter it and wash in water, then recrystallize from acetone.
Neutralize in 5% Na2CO3.
Wash and recrystallize again.
Dry in dissicator.
NOTES:
We dilute the soln. because HNO2 is formed. If its concentrated, the HNO2 decomposes as it dislikes its existance. One can ignore the adding ice, use 60ml 15% HCl, add 10g NaNO2, stir and cool in a VERY cold ice bath, then slowly add the 7g hexamine.
Yield is normally half the amount of hexamine (33% of theory I am told, 50% by hexamine).
***Here is data from SMDB on the topic:
This is R.D.X., but missing three oxygen atoms (one from each NO2 group). It uses no concentrated nitric acid. The only acid used is hydrochloric, and it doesn't even have to be very concentrated. This explosive is carcinogenic and toxic, contact should be avoided. However, this is perhaps the best explosive to make at home since it is easy to produce and powerful. The reason it's not used militarily is the low yield of 30% (I have seen 50% stated, but this means that the weight yielded is 50% of the weight of hexamethylenetetramine used, e.g. 3.5 grams of C.T.M.T.N.A. from 7 grams of hexamethylenetetramine.)
VoD is 7800 m/s at 1.57 g/cm3. Relative briscancy is 1.17. Lead block expansion is 370 cm3. At this density 2.5 grams of Mercury Fulminate will cause detonation, at 0.85 g/cm3 a mere 0.3 grams of Mercury Fulmiate will suffice!
You will need:
7g of hexamethylenetetramine,
60mL of 15% hydrochloric acid,
10.5g of sodium nitrite,
Distilled water,
50mL of 10% sodium carbonate solution,
20mL of acetone,
1g of sodium carbonate,
An ice bath,
A 150mL beaker,
A thermometer,
A filter funnel,
Three filter papers.
1) Dissolve the hexamine in 25mL of water and add the hydrochloric acid in the 150mL beaker.
2) Cool this to 0*C in the ice bath, and add a solution of the sodium nitrite in 50mL of water, while stirring.
3) Leave the solution to react overnight at 5*C, and then filter out the crystals.
4) Wash them with 200mL of water, then the sodium carbonate solution, then another 200mL of water.
5) Dissolve them in the acetone at around 40*C, add the 1 gram of sodium carbonate, and stir for 5 minutes.
6) Filter the solution
7) Dump the filtrate into 100mL of cold water in the other 150mL beaker to precipitate the crystals.
7) Filter them out, and leave them to dry in a warm, dry place in a thin layer
I'd previously tried to get R-salt by bubbling N2O3 through 20g hexamine, 100ml 32% HCl and 150ml water, cooled to 5°C. A precipitate did seem to form (solution turned white/turbid) but temperature gets out of control and solution fumed off as you get if r-salt is added to hot acid (its not stable in acid solution, far worse if its hot). If one was going to attempt this you will need to use a slurry of crushed ice, external cooling wont work.
Anyway, heres conventional r-salt through NaNO2/HCl/hexamine. Three solutions were made, one containing 60g 35% HCl in 100ml water, one containing 40g NaNO2 in 80ml water and one containing 20g hexamine and 60g HCl in 100ml water. The NaNO2/HCl solutions are combined, producing blue solution of nitrous acid. This is then added to the hexamine/HCl <0°C. The foam filtered off, dried. Yield was just over 50% right on the documented yield. Melting point on rapid heating was 110°C, close enough to documented temp of 106-7°C. The other possible product (dinitrosopentamethylenetetramine) melts at 207°C so easy to tell apart.
By not mixing the up the nitrous acid first, theres a lot more foaming and heating and often I end up with nothing at all.
R-salt burns easily with soft orange flame leaving residue, with noise but not as vigourously as RDX. Ive never tried to detonate it.
R-salt / RDX eutectic
R-salt forms a relatively low melting eutectic at about a 50/50 mix with RDX which results in a very high energy composition . PATR mentions a minor proportion of a third material used in the composition . Possibly the ethylene or propylene pseudo-nitrosite could also be useful in such a meltable composition .
With regards to use of N2O3 for R-Salt ,
some means of pH control might give better yields . For example , dissolving
hexamine in white vinegar ( 4 or 5% acetic acid ) in excess and then adjusting
the pH if necessary with HCl , chilling very cold and nitrosating , could give better yields than using HCl alone as the acid as when sodium nitrite is used as the nitrosation reagent . When the solid nitrite is used it would tend to buffer the reaction pH by virtue of the sodium it contains . But the use of N2O3 would
be absent that buffering effect which
would cause the reaction mixture to become more and more acidic as the nitrosation proceeds . The effect would be lessened in a reaction mixture which
is mainly acidified with acetic acid and where HCl is present in lower amount .
There is also the possibility that this approach would not work at all , especially if the acetic acid itself should be nitrosated , or if the dilution is too great for the reaction mixture of this sort to react as wished
It is mentioned in PATR 2700 that r-salt can be nitrated to RDX with H2SO4/AN in >90% yield. If N2O3 drawn off H2SO4/AN/starch was to work it could be a convenient way to RDX, requiring no nitric acid or nitrites. Note that 50% R-salt yield is based on 1M hexamine creating 1M R-salt, with RDX theoretically 2M are created for every 1M hexamine in ammonium salt is used. This means, through this route, at best you can expect a 25% yield of RDX from hexamine.
PATR states that a mixture of R-salt and NG kept at 90C for 5 days showed no apparent decomposition ? Possibly a misprint , because that would seem to indicate stabilizing properties for R-salt towards nitroesters which if true is very interesting . If this is general , R-salt could possibly have value as an energetic stabilizer as well as filler for ETN melt and other low melting compositions , and possible usefulness in many other nitroester containing compositions .
Urbanski describes 84% yields of R-salt reported by Aubertein giving detailed instructions for synthesis
P. Aubertein , Mem. Poudres 33 , 227 ,
( 1951 )
Also in the same journal a method for production on a semi-commercial scale is reported by Ficheroulle and Kovache
H. Ficheroulle and A. Kovache , Mem. Poudres 33 , 241 , ( 1951 )
These would be interesting references if anyone has access and may share these articles
R-salt reportedly has 125% the output of TNT and yet it is made under fairly mild conditions . That alone makes it interesting and even better if the yield could be increased over the 50% without too much added difficulty . I hope someone will get a look at those 1951 articles in Memorial of the Powders .
The reference in PATR to the 90C heat test
for an R-salt and NG mixture is also intriguing , and it makes me wonder what may be the result of mixtures with other nitroesters like ethylene glycol dinitrate ,
and erythritol tetranitrate , IF of course the information in PATR is accurate and
not a misprint like some others we have seen .
In the thread about HMX there was a high yield reported for DNPT by a reaction scheme which may be adaptable to R-salt using different proportions and pH . An experiment by a forum member BASF was unable to confirm the method for DNPT ,
which seemed to be a low temperature variation on something similar to the
K process for RDX , but intended for a nitrosamine product . Such a
" no hexamine " method for R-salt from
reaction scheme which proceeds from a mixture of NH4 and CH2O providing
" nascent hexamine " as the precursor for the nitrosamine would be an interesting simplification , similarly as is the case for those of us who make out own hexamine anyway and never drop it out of solution as hexamine free base , but rather as the dinitrate .
R-salt is a chemically reactive material and
I have wondered also what is its reactivity towards an organic peroxide , such as MEKP , or a liquid MEKP / AP mixture , or in an AP melt
First I added 30 ml of 31.45% HCl to 50 ml water and this was mixed with 18 grams KNO2 in 30 ml water. I then added 7 grams hex to 50 ml water.
http://img.photobucket.com/albums/v78/wolfhound/ct1.jpg
At < 0C I added the nitrous acid to the hexamine solution. At first I thought nothing was happening but then it foamed up quite a bit, almost to the top of the reaction vessel. Then the foam went down as the gas escaped.
http://img.photobucket.com/albums/v78/wolfhound/ct2.jpg
http://img.photobucket.com/albums/v78/wolfhound/ct3.jpg
This was then filtered and now it's drying. I don't know how great the yield is since it's a big air filled blob of wet product still, but I'll measure when it's dry. Either way I'm just happy that it worked.
http://img.photobucket.com/albums/v78/wolfhound/ct4.jpg
I think the first time I tried it I actually did get something but it was an uncontrolled foaming with lots of NO2(?) coming off. So now all that's left is drying and weighing. Just one more question, is there any reason to wash the product to neutralize it? Thank you for the help and I appreciate any input
Also I remember reading that CTMTNA forms a low melting point and easily castable eutectic in a 50:50 ratio with RDX though I'm not sure what defines a "low melting point" IMO this would be have slightly more power than composition B and be of similar balance.
Also, if your nitration/oxydation to RDX is not to be and you can perfect your yeild and ecomany when synthesising CTMTNA, you could try plastisisng it with a 20% mix of 4:1 by mass NG/MHN. Although the heat output would be lower than than RDX/NG/MHN plastique I'd bet the velocity would still be around 7800m/s for a fully plastisised though TOXIC mass... (gloves)
There are a couple of ideas which I have considered with
regards to the production of R-salt . I always make my
own hexamine from the reaction of paraformaldehyde mildewcide crystals and 28% ammonia blueprint developer
in excess , bringing the completed reaction to boiling after
all is in solution to drive off any unreacted ammonia and
leave a strong solution of pure hexamine in nearly quantitative yield , based on the 96% purity of the paraformaldehyde crystals used for the synthesis .
The solution may be boiled down until crystals of hexamine
just appear and then the heating stopped . Upon cooling the hexamine will redissolve due to the inverse solubility
curve of hexamine with regards to temperature , leaving
a cold saturated solution . Hexamine dinitrate can be
precipitated from the freezing cold solution by just neutralizing with HNO3 in no great excess . The residual
solution contains some dissolved hexamine dinitrate which
is generally lost since the solution cannot be evaporated
by boiling at ordinary temperature . But the solution
from filtration of HDN can be further used directly in synthesis instead of simply being discarded as waste .
The HDN solution can be mixed with a 15% excess of theory
of hydrogen peroxide and kept in the freezer for the precipitation of HMTD which is complete after a couple of days . And it seems likely that the cold HDN solution could also be used for the production of R-salt by reducing the amount of H2SO4 somewhat for one of the Aubertein
syntheses , to adjust the pH accounting for the HNO3 present in the HDN which is in solution . A useful byproduct
would thus be salvaged from a waste solution from the
synthesis of the HDN precursor for RDX , improving the economy of the process . Also the R-salt produced would
be of value because of its ability to form useful eutectics with
any RDX ultimately made from the HDN which was recovered
as crystals earlier in the process . This production of R-salt
as a byproduct would offset the losses which are inherent in the relatively inefficient nitrolysis of HDN to RDX . A further
improvement in efficency may be obtained by using the diluted nitrolysis mixture from filtration of the RDX , which
contains fairly concentrated HNO3 , for neutralization of
subsequent batches of concentrated hexamine solution to
produce more HDN and R-salt . By this scheme otherwise
wasted byproducts are recycled in the process , which would be of significant value in any large scale production
Now that I think about it , I have never seen the reaction stated either , so here is what I suppose is most likely .
(CH2)6N4 + 3 HNO2 ----> (CH2)3N6O3 + NH3 + 3 CH2O
m.w. 140.19 hexamine --------- m.w. 174.13 TMTN
100% yield of TMTN would be 1.2421 grams
per each 1 gram of hexamine .
The best yield reported by Aubertein in Experiment 19 was
64.9% of theory which amounts to .806 grams of TMTN
per each 1 gram of hexamine .
The equation I provided above is probably correct .
Evidently the yield figure of 84% attributed to Aubertein by Urbanski on page 122 of volume 3 , is an error .
It may be worthwhile also to experiment with nitric acid
as the acid used in whole or in part in the process for producing TMTN , and using Hexamine Dinitrate as the form of hexamine . My first experiment for TMTN will likely be
of that nature , simply to satisfy my curiosity . I have a
hunch , an intuition that this could work fine also , and it would be interesting to discover what the effect would be on the yield .
The acidic conditions prevent the recombination of
the byproduct ammonia and formaldehyde to reform
the original hexamine and this parallels the situation
for RDX . You see the formation of hexamine only
occurs in alkaline reaction medium where the ammonia
can be free and the formaldehyde is also reactive .
In acidic systems there is a different reaction which
leads to methylamine derivatives and di and tri-methylamine derivatives instead of the hexamethylene
cyclisation favored in alkaline systems .
Even for the case where it was once believed that
an additional yield of RDX could be gotten from the
reforming of hexamine from the decomposition products , this has been proven to be untrue , but involves some
complex intermediates of a different nature which form
in the extreme nitration mixtures for RDX , and then are converted to RDX by a series of reactions .
That is unlikely to be possible in the aqueous system
used for producing TMTN .
One thing that could be done is to use the waste filtrate
from TMTN for production of formite . Adding the proper amount of ammonium nitrate and urea would cycle the waste formaldehyde to methylamine nitrate and the di and trimethylamine nitrates also in lesser amount . These products along with additional AN and urea ,
could be mixed to form a melt castable which would be a high energy composition nearly equivalent to TNT and probably cap sensitive . If not , the TMTN could be used
as a booster for it .
Could just AN be used to convert the waste formaldehyde into Methylamine nitrate?
4CH2O + 5NH4NO3 = 4CH3NH2 + 6HNO3 + H2O
CH3NH3 + HNO3 ----> CH3NH2*HNO3
Or would that reaction not progress
A simultaneous reaction is not practical because the
methylamine formation is favored by high temperatures ,
while the TMTN formation requires low temperatures .
It goes something like you have it but the reaction is more complex with secondary reactions and byproducts which are reduced and involved with yet another reaction with urea . There are a couple of patents concerning this . I can't dig them up right now as I am salvaging what I can from about four years worth of data loss after the main drive has failed in my computer , which should keep me busy for weeks trying to get a fraction of the data restored from what part of it was backed up . The drive failure sneaked up on me with read and write errrors that have corrupted everything pretty badly that was a larger file . A lot of the small pdfs. I may get back but that is about it .
With regards to utilizing the waste solutions , it is something mainly pertinent to industrial scale production which would seem worth the trouble for economic and environmental considerations . For lab scale syntheses it is hardly worth the trouble . This process would also be predicated on the
success of using nitric acid instead of the sulfuric or hydrochloric acid as has been described for TMTN , so that
there would only be nitrates in the final mixture . This is part of my interest in seeing if the TMTN can indeed be made
from HDN as a starting material , and using nitric acid to
achieve the pH 1 reaction condition , not only to see if the
yield of TMTN may be improved , but also because the value
of the waste solution for further reaction may be improved ....
not only for potential value in regards to formite which may or may not proceed well , but simply knowing that neutralization with ammonia and evaporating would lead
to a useful residue of nitrates and hexamine , so that there
would be no waste output from the TMTN production .
Efficiency is everything with regards to chemical plants ,
so zero waste is an important goal for the economic and environmental concerns ......waste not , want not
The two " formite " ( formaldehyde / AN reaction mixture ) patents that I know about are
EP0037862
GB1548827
Patent related to such mixtures value in cast melts
US1968158
Related reaction under alkaline conditions which
produces hexamine instead
US3660182
Slurry related hexamine containing AN composition
US3496040
AND thats all from SMDB. Special credit to Rosco Bodine.
I have posted data gethered from SMDB on the subject, and posted a few .pdf's I originally got there.
Its preparation is VERY simple and OTC. It uses HCl, NaNO2 and Hexamine.
Hexamine can be prepared from formaldehyde and ammonium hydroxide, formaldehyde by oxidation of methanol. Ammonium hydroxide by making ammonia from NaOH and an ammonium salt (Ammonium Nitrate is best) and water, and by bubbling the ammonia through cold water. I say to use AN because it creates NaNO3 as a 'waste product' which can be then reduced to NaNO2 for the synth.
NaNO2 can be made from NaNO3 by reduction in melt with lead, or by other methods detailed on this board.
HCl can be made by adding table salt to H2SO4 and bubbling the HCl gas through cold water. Its easier to buy it OTC.
PROPERTIES OF R-SALT:
VoD 7300m/s at 1.5g/cc.
LB expansion 370cc.
Soluble in boiling alcohol, slightly in H2O.
At 1.57g/cc requires 2.5g Mercury fulminate, and VoD is 7800m/s.
Decomp w/ evolution of ammonia and formaldehyde on contact with NaOH.
Explodes on contact with conc. H2SO4.
SYNTHISES of R-SALT:
7g Hexamine is dissolved in 50ml water. Mix with 400g ice in beaker. Add 26ml conc HCl.
Dissolve 10.4g NaNO2 in 50ml water, pour into beaker with ice.
Let soln. stand a hour.
Filter it and wash in water, then recrystallize from acetone.
Neutralize in 5% Na2CO3.
Wash and recrystallize again.
Dry in dissicator.
NOTES:
We dilute the soln. because HNO2 is formed. If its concentrated, the HNO2 decomposes as it dislikes its existance. One can ignore the adding ice, use 60ml 15% HCl, add 10g NaNO2, stir and cool in a VERY cold ice bath, then slowly add the 7g hexamine.
Yield is normally half the amount of hexamine (33% of theory I am told, 50% by hexamine).
***Here is data from SMDB on the topic:
This is R.D.X., but missing three oxygen atoms (one from each NO2 group). It uses no concentrated nitric acid. The only acid used is hydrochloric, and it doesn't even have to be very concentrated. This explosive is carcinogenic and toxic, contact should be avoided. However, this is perhaps the best explosive to make at home since it is easy to produce and powerful. The reason it's not used militarily is the low yield of 30% (I have seen 50% stated, but this means that the weight yielded is 50% of the weight of hexamethylenetetramine used, e.g. 3.5 grams of C.T.M.T.N.A. from 7 grams of hexamethylenetetramine.)
VoD is 7800 m/s at 1.57 g/cm3. Relative briscancy is 1.17. Lead block expansion is 370 cm3. At this density 2.5 grams of Mercury Fulminate will cause detonation, at 0.85 g/cm3 a mere 0.3 grams of Mercury Fulmiate will suffice!
You will need:
7g of hexamethylenetetramine,
60mL of 15% hydrochloric acid,
10.5g of sodium nitrite,
Distilled water,
50mL of 10% sodium carbonate solution,
20mL of acetone,
1g of sodium carbonate,
An ice bath,
A 150mL beaker,
A thermometer,
A filter funnel,
Three filter papers.
1) Dissolve the hexamine in 25mL of water and add the hydrochloric acid in the 150mL beaker.
2) Cool this to 0*C in the ice bath, and add a solution of the sodium nitrite in 50mL of water, while stirring.
3) Leave the solution to react overnight at 5*C, and then filter out the crystals.
4) Wash them with 200mL of water, then the sodium carbonate solution, then another 200mL of water.
5) Dissolve them in the acetone at around 40*C, add the 1 gram of sodium carbonate, and stir for 5 minutes.
6) Filter the solution
7) Dump the filtrate into 100mL of cold water in the other 150mL beaker to precipitate the crystals.
7) Filter them out, and leave them to dry in a warm, dry place in a thin layer
I'd previously tried to get R-salt by bubbling N2O3 through 20g hexamine, 100ml 32% HCl and 150ml water, cooled to 5°C. A precipitate did seem to form (solution turned white/turbid) but temperature gets out of control and solution fumed off as you get if r-salt is added to hot acid (its not stable in acid solution, far worse if its hot). If one was going to attempt this you will need to use a slurry of crushed ice, external cooling wont work.
Anyway, heres conventional r-salt through NaNO2/HCl/hexamine. Three solutions were made, one containing 60g 35% HCl in 100ml water, one containing 40g NaNO2 in 80ml water and one containing 20g hexamine and 60g HCl in 100ml water. The NaNO2/HCl solutions are combined, producing blue solution of nitrous acid. This is then added to the hexamine/HCl <0°C. The foam filtered off, dried. Yield was just over 50% right on the documented yield. Melting point on rapid heating was 110°C, close enough to documented temp of 106-7°C. The other possible product (dinitrosopentamethylenetetramine) melts at 207°C so easy to tell apart.
By not mixing the up the nitrous acid first, theres a lot more foaming and heating and often I end up with nothing at all.
R-salt burns easily with soft orange flame leaving residue, with noise but not as vigourously as RDX. Ive never tried to detonate it.
R-salt / RDX eutectic
R-salt forms a relatively low melting eutectic at about a 50/50 mix with RDX which results in a very high energy composition . PATR mentions a minor proportion of a third material used in the composition . Possibly the ethylene or propylene pseudo-nitrosite could also be useful in such a meltable composition .
With regards to use of N2O3 for R-Salt ,
some means of pH control might give better yields . For example , dissolving
hexamine in white vinegar ( 4 or 5% acetic acid ) in excess and then adjusting
the pH if necessary with HCl , chilling very cold and nitrosating , could give better yields than using HCl alone as the acid as when sodium nitrite is used as the nitrosation reagent . When the solid nitrite is used it would tend to buffer the reaction pH by virtue of the sodium it contains . But the use of N2O3 would
be absent that buffering effect which
would cause the reaction mixture to become more and more acidic as the nitrosation proceeds . The effect would be lessened in a reaction mixture which
is mainly acidified with acetic acid and where HCl is present in lower amount .
There is also the possibility that this approach would not work at all , especially if the acetic acid itself should be nitrosated , or if the dilution is too great for the reaction mixture of this sort to react as wished
It is mentioned in PATR 2700 that r-salt can be nitrated to RDX with H2SO4/AN in >90% yield. If N2O3 drawn off H2SO4/AN/starch was to work it could be a convenient way to RDX, requiring no nitric acid or nitrites. Note that 50% R-salt yield is based on 1M hexamine creating 1M R-salt, with RDX theoretically 2M are created for every 1M hexamine in ammonium salt is used. This means, through this route, at best you can expect a 25% yield of RDX from hexamine.
PATR states that a mixture of R-salt and NG kept at 90C for 5 days showed no apparent decomposition ? Possibly a misprint , because that would seem to indicate stabilizing properties for R-salt towards nitroesters which if true is very interesting . If this is general , R-salt could possibly have value as an energetic stabilizer as well as filler for ETN melt and other low melting compositions , and possible usefulness in many other nitroester containing compositions .
Urbanski describes 84% yields of R-salt reported by Aubertein giving detailed instructions for synthesis
P. Aubertein , Mem. Poudres 33 , 227 ,
( 1951 )
Also in the same journal a method for production on a semi-commercial scale is reported by Ficheroulle and Kovache
H. Ficheroulle and A. Kovache , Mem. Poudres 33 , 241 , ( 1951 )
These would be interesting references if anyone has access and may share these articles
R-salt reportedly has 125% the output of TNT and yet it is made under fairly mild conditions . That alone makes it interesting and even better if the yield could be increased over the 50% without too much added difficulty . I hope someone will get a look at those 1951 articles in Memorial of the Powders .
The reference in PATR to the 90C heat test
for an R-salt and NG mixture is also intriguing , and it makes me wonder what may be the result of mixtures with other nitroesters like ethylene glycol dinitrate ,
and erythritol tetranitrate , IF of course the information in PATR is accurate and
not a misprint like some others we have seen .
In the thread about HMX there was a high yield reported for DNPT by a reaction scheme which may be adaptable to R-salt using different proportions and pH . An experiment by a forum member BASF was unable to confirm the method for DNPT ,
which seemed to be a low temperature variation on something similar to the
K process for RDX , but intended for a nitrosamine product . Such a
" no hexamine " method for R-salt from
reaction scheme which proceeds from a mixture of NH4 and CH2O providing
" nascent hexamine " as the precursor for the nitrosamine would be an interesting simplification , similarly as is the case for those of us who make out own hexamine anyway and never drop it out of solution as hexamine free base , but rather as the dinitrate .
R-salt is a chemically reactive material and
I have wondered also what is its reactivity towards an organic peroxide , such as MEKP , or a liquid MEKP / AP mixture , or in an AP melt
First I added 30 ml of 31.45% HCl to 50 ml water and this was mixed with 18 grams KNO2 in 30 ml water. I then added 7 grams hex to 50 ml water.
http://img.photobucket.com/albums/v78/wolfhound/ct1.jpg
At < 0C I added the nitrous acid to the hexamine solution. At first I thought nothing was happening but then it foamed up quite a bit, almost to the top of the reaction vessel. Then the foam went down as the gas escaped.
http://img.photobucket.com/albums/v78/wolfhound/ct2.jpg
http://img.photobucket.com/albums/v78/wolfhound/ct3.jpg
This was then filtered and now it's drying. I don't know how great the yield is since it's a big air filled blob of wet product still, but I'll measure when it's dry. Either way I'm just happy that it worked.
http://img.photobucket.com/albums/v78/wolfhound/ct4.jpg
I think the first time I tried it I actually did get something but it was an uncontrolled foaming with lots of NO2(?) coming off. So now all that's left is drying and weighing. Just one more question, is there any reason to wash the product to neutralize it? Thank you for the help and I appreciate any input
Also I remember reading that CTMTNA forms a low melting point and easily castable eutectic in a 50:50 ratio with RDX though I'm not sure what defines a "low melting point" IMO this would be have slightly more power than composition B and be of similar balance.
Also, if your nitration/oxydation to RDX is not to be and you can perfect your yeild and ecomany when synthesising CTMTNA, you could try plastisisng it with a 20% mix of 4:1 by mass NG/MHN. Although the heat output would be lower than than RDX/NG/MHN plastique I'd bet the velocity would still be around 7800m/s for a fully plastisised though TOXIC mass... (gloves)
There are a couple of ideas which I have considered with
regards to the production of R-salt . I always make my
own hexamine from the reaction of paraformaldehyde mildewcide crystals and 28% ammonia blueprint developer
in excess , bringing the completed reaction to boiling after
all is in solution to drive off any unreacted ammonia and
leave a strong solution of pure hexamine in nearly quantitative yield , based on the 96% purity of the paraformaldehyde crystals used for the synthesis .
The solution may be boiled down until crystals of hexamine
just appear and then the heating stopped . Upon cooling the hexamine will redissolve due to the inverse solubility
curve of hexamine with regards to temperature , leaving
a cold saturated solution . Hexamine dinitrate can be
precipitated from the freezing cold solution by just neutralizing with HNO3 in no great excess . The residual
solution contains some dissolved hexamine dinitrate which
is generally lost since the solution cannot be evaporated
by boiling at ordinary temperature . But the solution
from filtration of HDN can be further used directly in synthesis instead of simply being discarded as waste .
The HDN solution can be mixed with a 15% excess of theory
of hydrogen peroxide and kept in the freezer for the precipitation of HMTD which is complete after a couple of days . And it seems likely that the cold HDN solution could also be used for the production of R-salt by reducing the amount of H2SO4 somewhat for one of the Aubertein
syntheses , to adjust the pH accounting for the HNO3 present in the HDN which is in solution . A useful byproduct
would thus be salvaged from a waste solution from the
synthesis of the HDN precursor for RDX , improving the economy of the process . Also the R-salt produced would
be of value because of its ability to form useful eutectics with
any RDX ultimately made from the HDN which was recovered
as crystals earlier in the process . This production of R-salt
as a byproduct would offset the losses which are inherent in the relatively inefficient nitrolysis of HDN to RDX . A further
improvement in efficency may be obtained by using the diluted nitrolysis mixture from filtration of the RDX , which
contains fairly concentrated HNO3 , for neutralization of
subsequent batches of concentrated hexamine solution to
produce more HDN and R-salt . By this scheme otherwise
wasted byproducts are recycled in the process , which would be of significant value in any large scale production
Now that I think about it , I have never seen the reaction stated either , so here is what I suppose is most likely .
(CH2)6N4 + 3 HNO2 ----> (CH2)3N6O3 + NH3 + 3 CH2O
m.w. 140.19 hexamine --------- m.w. 174.13 TMTN
100% yield of TMTN would be 1.2421 grams
per each 1 gram of hexamine .
The best yield reported by Aubertein in Experiment 19 was
64.9% of theory which amounts to .806 grams of TMTN
per each 1 gram of hexamine .
The equation I provided above is probably correct .
Evidently the yield figure of 84% attributed to Aubertein by Urbanski on page 122 of volume 3 , is an error .
It may be worthwhile also to experiment with nitric acid
as the acid used in whole or in part in the process for producing TMTN , and using Hexamine Dinitrate as the form of hexamine . My first experiment for TMTN will likely be
of that nature , simply to satisfy my curiosity . I have a
hunch , an intuition that this could work fine also , and it would be interesting to discover what the effect would be on the yield .
The acidic conditions prevent the recombination of
the byproduct ammonia and formaldehyde to reform
the original hexamine and this parallels the situation
for RDX . You see the formation of hexamine only
occurs in alkaline reaction medium where the ammonia
can be free and the formaldehyde is also reactive .
In acidic systems there is a different reaction which
leads to methylamine derivatives and di and tri-methylamine derivatives instead of the hexamethylene
cyclisation favored in alkaline systems .
Even for the case where it was once believed that
an additional yield of RDX could be gotten from the
reforming of hexamine from the decomposition products , this has been proven to be untrue , but involves some
complex intermediates of a different nature which form
in the extreme nitration mixtures for RDX , and then are converted to RDX by a series of reactions .
That is unlikely to be possible in the aqueous system
used for producing TMTN .
One thing that could be done is to use the waste filtrate
from TMTN for production of formite . Adding the proper amount of ammonium nitrate and urea would cycle the waste formaldehyde to methylamine nitrate and the di and trimethylamine nitrates also in lesser amount . These products along with additional AN and urea ,
could be mixed to form a melt castable which would be a high energy composition nearly equivalent to TNT and probably cap sensitive . If not , the TMTN could be used
as a booster for it .
Could just AN be used to convert the waste formaldehyde into Methylamine nitrate?
4CH2O + 5NH4NO3 = 4CH3NH2 + 6HNO3 + H2O
CH3NH3 + HNO3 ----> CH3NH2*HNO3
Or would that reaction not progress
A simultaneous reaction is not practical because the
methylamine formation is favored by high temperatures ,
while the TMTN formation requires low temperatures .
It goes something like you have it but the reaction is more complex with secondary reactions and byproducts which are reduced and involved with yet another reaction with urea . There are a couple of patents concerning this . I can't dig them up right now as I am salvaging what I can from about four years worth of data loss after the main drive has failed in my computer , which should keep me busy for weeks trying to get a fraction of the data restored from what part of it was backed up . The drive failure sneaked up on me with read and write errrors that have corrupted everything pretty badly that was a larger file . A lot of the small pdfs. I may get back but that is about it .
With regards to utilizing the waste solutions , it is something mainly pertinent to industrial scale production which would seem worth the trouble for economic and environmental considerations . For lab scale syntheses it is hardly worth the trouble . This process would also be predicated on the
success of using nitric acid instead of the sulfuric or hydrochloric acid as has been described for TMTN , so that
there would only be nitrates in the final mixture . This is part of my interest in seeing if the TMTN can indeed be made
from HDN as a starting material , and using nitric acid to
achieve the pH 1 reaction condition , not only to see if the
yield of TMTN may be improved , but also because the value
of the waste solution for further reaction may be improved ....
not only for potential value in regards to formite which may or may not proceed well , but simply knowing that neutralization with ammonia and evaporating would lead
to a useful residue of nitrates and hexamine , so that there
would be no waste output from the TMTN production .
Efficiency is everything with regards to chemical plants ,
so zero waste is an important goal for the economic and environmental concerns ......waste not , want not
The two " formite " ( formaldehyde / AN reaction mixture ) patents that I know about are
EP0037862
GB1548827
Patent related to such mixtures value in cast melts
US1968158
Related reaction under alkaline conditions which
produces hexamine instead
US3660182
Slurry related hexamine containing AN composition
US3496040
AND thats all from SMDB. Special credit to Rosco Bodine.
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