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smokeup
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I heard you use a normall solid binder, heat to liquid, mix, pour into mold, compress, wait to solidify.
Just make sure the heating and compressing dont trigger it.
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Laboratory of Liptakov
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Reflux condenser.
Cu tube 10/12, long 600mm.
Jacob's ladder condensation.........LL
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markx
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For the transesterification of castor oil? For that purpose it is overkill by function, but if one enjoys the process then why not. I personally would
have just screwed the lid lightly on the glass jar to prevent the methanol from evaporating. In fact I have conducted the synthesis in an open flask
without any problems and without any preventative measures to avoid the escape of methanol....it really is not that volatile by nature.
Exact science is a figment of imagination.......
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Hennig Brand
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Methanol is quite toxic and its boiling point is less than 65C. I used a long piece of glass tubing and a rubber stopper to make a simple air cooled
reflux condenser the last time I performed the trans-esterification reaction indoors. The heat transfer properties of copper are very much superior to
glass (and pretty much every other common material); as long as the chemicals involved in a particular application are compatible with copper it can
be used. Glass is much closer to being completely inert, however, and it provided all the cooling I needed.
"A risk-free world is a very dull world, one from which we are apt to learn little of consequence." -Geerat Vermeij
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Laboratory of Liptakov
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methyl ricinoleate
Markx is right. No need cooler. Glasses can be closed. The steam pressure is small. Even at 80C cap holds. No problems. The temperature is maintained
at 70C for 4 hours. A sample of the reaction: 19.5 g + 0.5 g of 96% H2SO4. It is necessary to wait for the separation of the layers. The lower part
has to be glycerine and the upper portion of the solution of methyl ricinoleate. Distribution takes 12 hours ....? ....LL
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markx
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Quote: Originally posted by Laboratory of Liptakov | A sample of the reaction: 19.5 g + 0.5 g of 96% H2SO4. It is necessary to wait for the separation of the layers. The lower part has to be glycerine
and the upper portion of the solution of methyl ricinoleate. Distribution takes 12 hours ....? ....LL |
Sulfuric acid? Did you use the acid catalysed transesterification process? Base catalysed transesterification tends to work much faster due to the
reaction mechanism specifics:
http://www.icrepq.com/icrepq%2711/549-encinar.pdf
First separation of layers with base catalyst process can be observed quite quickly...in less than an hour from the start of reaction, but complete
separation can take up to 12 hours (depending on ambient temperature).
Exact science is a figment of imagination.......
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Laboratory of Liptakov
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r.oleate
I followed the instructions from page 5 this thread:
methylricinoleate.pdf
Unfortunately I have bad results, methyl ricinoleate failed to produce. I will return to this later. Thank you for your help and for the last link. I
need very precise instructions. Machine translation trouble. Few understand. I do not want to be a burden.
I prefer to bring results. As is detonography etc. ...........LL
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Hennig Brand
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Glass Reaction Vessel Pressure Calculation
I decided to work through this, just for my own interest mostly. Assuming ideal behavior, will use Raoult's Law and Dalton's Law. I may have made
calculation errors.
Information on castor oil came from this site:
http://www.scbt.com/datasheet-214671-castor-oil.html
Castor Oil - C57H104O9
MW = 933.61g/mol
Density = 0.961g/mL
Vapor pressure at 80C came from the following site:
http://www.engineersedge.com/fluid_flow/fluid_data.htm
Castor Oil Vapor Pressure at 80C ~= 0 kPa (very, very low)
Methanol - CH3OH
MW = 32.04g/mol
Density = 0.792g/mL
Vapor pressure at 80C ~= 182kPa
(Methanol values from Wiki pages)
Assume using equal volumes of castor oil and methanol as Nitro-
genes suggested here:
http://www.sciencemadness.org/talk/viewthread.php?tid=6151&a...
Basis of 100mL of each reactant
Moles of Castor oil = 100mL * (0.961g/mL) / (933.61g/mol) = 0.1029moles
Moles of Methanol = 100mL * (0.792g/mL) / (32.04g/mol) = 2.472moles
Mole Fraction of Castor oil in liquid = 0.1029 / (0.1029 + 2.472) = 0.040
Mole Fraction of Methanol in liquid = 2.472 / (0.1029 + 2.472) = 0.960
Pressure Total = Pvap_castor * X_castor + Pvap_MeOH * X_MeOH
Pressure Total = 0 * 0.040 + 182kPa * 0.960
Pressure Total = 174.72 kPa (atmospheric is 101.32kPa)
This is of course the maximum pressure at the start of the reaction at 80C; since as the methanol is consumed its liquid molar fraction will drop and
so too will the internal pressure. I didn't account for the air in the head space, but its pressure will not be significant compared to the vapor
pressure of methanol at 80C.
It is amazing how much internal positive pressure undamaged, well made, glass bottles can take. There is a big difference between a champagne bottle,
built to handle pressure, and a thin walled pickle jar though. Also bottles, even of the same type, are never completely uniform and some have
imperfections which make them much weaker. A small crack or imperfection can make a glass vessel fail at very low pressures.
Attached is a study done on glass bottle destructive testing.
Attachment: Analysis of Brittle Fracture of Soda Glass Bottles under Hydrostatic Pressure.pdf (274kB) This file has been downloaded 650 times
[Edited on 3-12-2014 by Hennig Brand]
"A risk-free world is a very dull world, one from which we are apt to learn little of consequence." -Geerat Vermeij
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markx
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174kPa would be the worst case scenario, assuming that the whole reactor is at 80C. If one uses a tall(ish) reactor with only the bottom part of
reagents submerged in the thermostat then the upper part of reactor would act as a natural cooler, provoking condesation and relieving the pressure
gradient significantly. And 80C in my personal experience is too much for practical transesterification. I speak of my own experiences and I have
noticed that when you go that high with the temperature, you will saponify the oil, spend the hydroxide on it and are left with a sticky well
emulsified mess of oil, soap and unreacted alcohols. It may look similar to transesterification at some stage, but the phase separation will never
occur. So my suggestion would be to relax, turn the heat down and keep the catalyst content low. Try 40-50C and catalyst content below 1% oil mass
(dissolve the alkali in the methanol beforehand). Nice mellow conditions at the expense of reaction time but no need for extra coolers, pressures will
not burst reactors and ruin your day. At 50C the methanol vapour pressure should stay around 53kPa even if you submerge the whole system into the
water bath.
Exact science is a figment of imagination.......
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Hennig Brand
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Sounds like good suggestions. I haven't made any in several years. I made some two or three times, around that time, and I still have quite a bit of
it left.
"A risk-free world is a very dull world, one from which we are apt to learn little of consequence." -Geerat Vermeij
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PHILOU Zrealone
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Maybe something could be done with PVN (polyvinylnitrate = (-CH2-CHONO2-)n) as active, unsensitive plastic binder?
Density: 1.6 g/ccm
VOD: 7000 m/s @ 1.5 g/ccm (so 7600 m/s at max density)
Impact sensitivity: 10 Nm (IS PETN is 3 Nm)
For sure much better than common oils due to density increase and partly contributing to energy output.
PH Z (PHILOU Zrealone)
"Physic is all what never works; Chemistry is all what stinks and explodes!"-"Life that deadly disease, sexually transmitted."(W.Allen)
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Hennig Brand
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As long as the desired handling properties could be obtained it sounds great. Handling properties would come first, I would imagine, when considering
the binder & plasticizer components for a plastic explosive.
"A risk-free world is a very dull world, one from which we are apt to learn little of consequence." -Geerat Vermeij
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Laboratory of Liptakov
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PVN
In advance thank you all for your valuable contributions to methyl ricinoleate. Also: Polyvinyl Nitrate? VOD 7000 m / s and more? But: Is it possible
to produce? Glue Hercules, that is polyvinyl acetate. (contains PVA) Hydrolysis in methanol polyvinylalcohol arises. Polyvinyl alcohol is esterified
(HNO3) on polyvinyl nitrate. He tried to anyone? We know how to do it? Here is my best plastic ............VoD 0,0 m/s
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PHILOU Zrealone
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Polyvinyl alcohol pouches were used when I was working at Procter&Gamble R&D lab.
You get tiny plastic like bags with the liquid soap inside (high dutty liquid).
The liquid soap had to contain as little as possible moisture in a way to keep the bag integer, avoid leakage and mass sticking of the pouches.
The bag (owing to the hydrophilic nature of the hydroxy groups (PVA = (-CH2-CHOH-)n) dissolves into the wash-machine when in contact with warm or
tempered wash-water and set the washing liquid free into the hart of the clothes...
This technology is now common to encapsulate soaps for clothes and for dishwashing powders...
So now everybody knows where to look for it
[Edited on 5-12-2014 by PHILOU Zrealone]
PH Z (PHILOU Zrealone)
"Physic is all what never works; Chemistry is all what stinks and explodes!"-"Life that deadly disease, sexually transmitted."(W.Allen)
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Hennig Brand
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Very nice PHILOU, could you tell us a little bit about producing Polyvinyl Nitrate? It sounds like you have been through it and know what you are
talking about.
"A risk-free world is a very dull world, one from which we are apt to learn little of consequence." -Geerat Vermeij
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PHILOU Zrealone
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Same procedure as for polyols like cellulose nitrate, PETN, ETN.
Related compounds are ethyl nitrate, trimethylene glycol dinitrate and 1,3-butanediol dinitrate as being non viccinal nitric esters...there is a CH2
bridging between C holding a nitrate groupe.
H-(-CH2-CHONO2)n-H
n=1 CH3-CH2ONO2 = ethyl nitrate
n=2 CH3-CHONO2-CH2-CH2ONO2 = BGDN
n= Big = PVN
This family of compounds is linked to PETN family where the brindging is a C atom...they display good performances with low sensitivity to shock vs
parent pernitrated polyols with one nitrate per C atom
[Edited on 5-12-2014 by PHILOU Zrealone]
PH Z (PHILOU Zrealone)
"Physic is all what never works; Chemistry is all what stinks and explodes!"-"Life that deadly disease, sexually transmitted."(W.Allen)
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Laboratory of Liptakov
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polyvinylalcohol
Well done Phil. This is very important information. Polyvinyl Alcohol is thus a solid mass? A little plastic? It will be possible to use the empty
container clean? A basic mixed acid? HNO3-65 / H2SO4-96%? 40:60? That's all? The reaction temperature to 5C as ETN? Or 25C like PETN? The package will
be dissolved. Prior to esterification. Very interesting ........LL
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UnintentionalChaos
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Working with castor oil is problematic, because you can also transesterify to the alcohol group on the fatty acid chain. You need a very large excess
of methanol to avoid this. Also, usage of sulfuric acid will lead to ricinoleylsulfuric acid, where the alcohol is converted to a monosulfonate ester.
The sodium salt of this material is called turkey red oil and is a historically used surfactant in dying processes.
Department of Redundancy Department - Now with paperwork!
'In organic synthesis, we call decomposition products "crap", however this is not a IUPAC approved nomenclature.' -Nicodem
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markx
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Polyvinyl alcohol with different degrees of polymerisation is commercially available in powder form....no need to scavange and grind up the sufactant
capsules to obtain it
E.g.
http://www.carolina.com/specialty-chemicals-p-r/polyvinyl-al...
http://www.amazon.com/Polyvinyl-Alcohol-Purity-Powder-Bottle...
Just pick a source and order a sample...
It is widely used to encapsulate redispersion powder particles to prevent premature hardening during storage.
Exact science is a figment of imagination.......
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Laboratory of Liptakov
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Polyvinyl nitrate
Good work markx. We're only a small step from perfect plasticizer. And that's not all. Polyvinyl nitrate can be used independently. Or widely
represented in the mixture. Excellent substance. Universal. I hope to see you soon ....
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markx
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As a matter of fact I think that I still have a rather sizeable sample of POVAL brand PVOH powder somewhere in my lab....gotta keep an eye out for
it. Was not much good for the purpose that I ordered it, but perhaps the "alternative use" shall prove more successful.
Exact science is a figment of imagination.......
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