Sciencemadness Discussion Board
Not logged in [Login ]
Go To Bottom

Printable Version  
 Pages:  1  ..  8    10    12  ..  31
Author: Subject: Picric acid: different instructions
grndpndr
National Hazard
****




Posts: 508
Registered: 9-7-2006
Member Is Offline

Mood: No Mood

[*] posted on 8-6-2009 at 08:58


Slightly off topic. Anyone have info on trimonite?a melt castable tnp/mononitronapthalene. 7080 mps vod 1.6 gr cm/3.Curious as to info on this mix and dinitronapthalene/tri-
nitronapthalene-tnp melts or if they are to sensitive for secondarys/melts.
View user's profile View All Posts By User
Hennig Brand
International Hazard
*****




Posts: 1284
Registered: 7-6-2009
Member Is Offline

Mood: No Mood

[*] posted on 8-6-2009 at 15:08


http://www.ias.ac.in/jarch/proca/3/00000257.pdf
Derivatives Of Salicylic Acid-Part IX

Is this how the nitration using ASA proceeds? If it does and goes to Nitrosalicylic Acid then straight to TNP, With no DNP at all then this appears relavent, as nitrosalicylic acid from the little bit I read appears to be very stable and a poor explosive unlike DNP, as well as being much more insoluble in water than Picric Acid. Any insight is welcome.
I have been reading posts on Picric Acid where ever I can find them off and on for the last year or so, and experimenting albeit with only partial success.

Sorry to cut you off grndpndr, if I could answer your question I would. Your into something there I haven' t even heard of.

[Edited on 9-6-2009 by Hennig Brand]
View user's profile View All Posts By User
grndpndr
National Hazard
****




Posts: 508
Registered: 9-7-2006
Member Is Offline

Mood: No Mood

[*] posted on 8-6-2009 at 16:47


The mononitronapthalene/dynitronapthalene etc is completely seperate from the TNP synthesis.Mononitronaphthalene is used to lower the melt /mix temp of TNP and possibly use some of the excess O2 acting as a fuel if sufficient Mononitronapthalene is incorporated.
Read the entire thread, it covers most if not all the reasons for failed picric acid synthesis as well as the successful efforts. Assuming you have a reliable synthesis its either your precursors are contaminated/poor quality or your attention to detail is lacking as its generally accepted that picric acid is one of the easier synthesis to successfully complete. Regards,no offense intended but reading the thread should answer your questions.

[Edited on 9-6-2009 by grndpndr]
View user's profile View All Posts By User
Hennig Brand
International Hazard
*****




Posts: 1284
Registered: 7-6-2009
Member Is Offline

Mood: No Mood

[*] posted on 9-6-2009 at 06:29


Thanks for the reply. However this chemical(Picric Acid) has been giving many experimenter a hard time, to the extend that most appear to be giving up without getting satisfactory results(at least on the several forums I have read from). Everything is simple once you know it! Maybe the level that a lot of us are functioning at is making this more challenging than others perceive it to be. I find, as I believe others have here and elswhere, that the solutions, and evan the nature of the problems with this synthesis can be elusive.

Meant to put the edit here

[Edited on 9-6-2009 by Hennig Brand]
View user's profile View All Posts By User
Hennig Brand
International Hazard
*****




Posts: 1284
Registered: 7-6-2009
Member Is Offline

Mood: No Mood

[*] posted on 9-6-2009 at 06:55


I made Picric Acid several times in the last few days. The last time I used ASA bought pure as ASA powder USP. I used homemade nitric acid evan though in the past I used KNO3. I have not been able to find sodium nitrate. And rather than turn my Nitric Acid into Sodium Nitrate I thought it wise to use the acid. This would I reasoned make it easier to see what exactly it was I had at the end, with out worring about unknows before/after filtration. K sulphate much less soluble and problematic than sodium one. I didn' t take notes early on, but taking Rosco' s advice I do now(it realy helps to clarify the big picture).
For the first time a few days ago I used liquid Phenol as the feedstock.(ordered from town drugstore, fused USP, hydrate 8% water). I got a bad yeild of 13 grams from 20 of Phenol. However for the first time I had something that would easily detonate from a quick snap from a hammer on an anvil. Which has got me wondering about the nature of the impurities in the ASA route. Since my last experiment with ASA yeilded more than 20 grams of somthing that seems like Picric Acid to me, from 18 grams of ASA. This seems to be a respectable yeild, yet this stuff appears relatively insensitive. Is it possible to have a yeild like this and still be quite impure?, or so much as to impair function?
View user's profile View All Posts By User
497
National Hazard
****




Posts: 778
Registered: 6-10-2007
Member Is Offline

Mood: HSbF6

[*] posted on 9-6-2009 at 07:24


Test its solubility in water. 1 gram should dissolve in 15ml of boiling water or 78ml at 25*C. This should be fairly conclusive as to what your product is.

Also recrystallizing from boiling water should help purify it if there are impurities.

My guess is the 8% water in your phenol caused the lower yield. IIRC many people tried phenol and got lower yields, so maybe there's another factor..
View user's profile View All Posts By User
Hennig Brand
International Hazard
*****




Posts: 1284
Registered: 7-6-2009
Member Is Offline

Mood: No Mood

[*] posted on 9-6-2009 at 08:02


I think you are right about the water in the Phenol. I tried to get pure Phenol, a Kg actualy but the hazard charge was more than the cost of the Phenol. Maybe if sulphonation was done with very concentrated H2SO4 and no dilution was done prior to nitration this problem could be mitigated. Just remembered something. My H2SO4 was boiled down battery acid, boiled down last fall, and kept in an old miracle wip jar with a plastic lid. These jars are cheap and convenient, but after checking acid density it was clear that the top was leaky to the point that enough water was absorbed to bring acid concentration down to 82% or so. I guess I always thought before that a little extra water in this synthesis was not a big deal. I guess my extra water maybe turned out to be more than a little extra.(Acid water and Phenol water combined)
This is interesting regarding the water issue:
pg77 in Notes On Military Explosives by Erasmus M. Weaver Major General U.S. Army copywright 1917
Titled Manufacture of Picric Acid-Equel quantities by weight of concentrated H2SO4 and phenol are mixed in an iron vessel, stirred and heated by steam to from 212F to 250F(121C). From time to time tests are made to see if the phenol-sulphonic acid formed is soluble in cold water. When it is so the mixture is allowed to cool and twice the quantity of water is added. Then it goes on to talk about the nitration.

This seems like a lot of extra water. Unless deliberatly miss-leading, this seems to indicate that my little bit of water, probably not more than 15% would not be a problem. They did not discuss there yeild however.

[Edited on 9-6-2009 by Hennig Brand]

[Edited on 9-6-2009 by Hennig Brand]
View user's profile View All Posts By User
Hennig Brand
International Hazard
*****




Posts: 1284
Registered: 7-6-2009
Member Is Offline

Mood: No Mood

[*] posted on 9-6-2009 at 08:26


In the very early days of Picric Acid use as a munition I read that they initiated it with a booster of Picric Acid and KNO3 mixed
(something like 50/50 or 60/40 I believe). This mixture is more easily initiated than the pure Picric Acid, althiough significantly less gas volume, but still apparently a good initiator. This booster was of course set of with Mercury Fulminate. Had they failed to set it off with just Fulminate?(I haven' t found the answer). I had to search fairly hard to find the information I did find. I believe that Picric Acid the munition to be quite challenging to prepare, as compared to any old sample of TNP. As others have said it seems to be somthing of a lost art.
View user's profile View All Posts By User
grndpndr
National Hazard
****




Posts: 508
Registered: 9-7-2006
Member Is Offline

Mood: No Mood

[*] posted on 9-6-2009 at 14:06


I know improvised TNP to be sensitive to 1gr MF caps probably half that amount.Also MF and TNP as a composite cap also works well if the TNP/MF is kept well seperated from one another in an AL tubing preferably with some sort of inert coating inside the cap to be on the safe side.Not to forget being properly pressed!Though i think caps should be used almost immediately.Neighbors could become skittish if a composite cap became unstable and det in the garage lab.Very difficult to explain at 3am to grumpy LEO.In any event NO boosters are required to detonate Picric acid!!

I guess id start with my synthesis first and verify its ability to synthesise TNP.Then id look at my precursors, 85% H2SO4 is an obvious problem with any synthesis involving concentrated H2SO4. I question its ability to sulphonate ASA and absorb the water produced during nitration.Are you purifying the ASA correctly, using uncoated plain aspirin dissolved
in hot methanol and filtered.Finally is the nitrate salt of reasonable quality/correct amounts.

It just seems to me with reasonable quality precursors and an accurate synthesis followed correctly observing time and temps as well as observed color changes "TNP is a difficult synthesis to screw up" having no experience beyond using manufactured munitions/explosives. To beginning with imp binary's and commercial caps.To peroxides,various 'dynamite's', fulminate's. and finally basic nitrationsI find it hard to believe there is so much difficulty with picric acid?

Probably one of the most forgiving synthesis that are known in my very limited experience.personlly id look at every aspect of your procedure from the beginning.Reading all the available online synthesis compare them with Davis and Urbanski among many others.Examine the quality and quantity of your precursors. But again less than ideal percursors and method s were normally rewarded with good
quality TNP even before recyrstalizing or purifying.
And as far as
m ercury fulminate is concerned it easily detonates TNP when properly presed in the cap.In fact MF and TNP if properly isolated make an excellent composite cap
with picric acid being quite easily detonated with quite good power excceeding that of TNT in nearly all cases.I wish you better luck and a safe experiment.regards

[Edited on 9-6-2009 by grndpndr]

[Edited on 9-6-2009 by grndpndr]
View user's profile View All Posts By User
Hennig Brand
International Hazard
*****




Posts: 1284
Registered: 7-6-2009
Member Is Offline

Mood: No Mood

[*] posted on 9-6-2009 at 15:57


I am aware that people with descent picric acid have no problem detonating it. I was just wondering if some of the early problems with this explosive are being experienced again by many who experiment(mostly me). The processes may not have been perfected back then(it would be easier to learn from their mistakes and problems than our own)
Thank you for wishing me well. I do have a question but first I will explain my last proceedure with ASA and 95% drain cleaner acid. I used the 82% with the phenol experiment. So used 80mL of H2SO4 and 18g of ASA powder USP(comes pure and already powdered, pound at a time or more if you wish)Drug stores can order it and animal feed places often have it as it is put in their water for variuos ailments.Sulphonation was carried out between 110-140C and for more than four hours. It was allowed to cool to room temperature(sat in old car all night).Mixed acids consisted of 30mL H2SO4 90% and 30mL HNO3 90%.
For whatever reason about half was added dropwise over the course of about an hour with excellent stirring from a home made magnetic stirrer(just built two days ago). They are realy easy to build (half hour if have the couple things needed), using old computer power supply fan. I have a variable voltage/current PS so I use that to accuratly control the speed of the stir bar.Damn stir bar cost me $15 at the drug store, they must have seen me coming. Temperature was taken up through 40, 50, 60, 70 as last half of mixed acid was added. Temperature was regulated by feeding boiling water into a water bath around the beaker(on the magnetic stirrer).This second addition took most of an other hour. To heat further I had to use a hot plate. I used a sand bath and stirred by hand, but once the temp got up over a hundred I didn' t stirr much. The reaction seemed very slow, however I heated at 110-115C for 3 hours, all the while these small bubbles could be seen rising if I looked close.Temperature was controled with thyristor,commercial light dimmer 2000w(hot plate control is garbage, very cheaply made bimetal device). At the end let it cool then added about 280mL very cold water then just let it sit in fridge for many hours(didn' t take it in till no more nitrous fumes evolved).Yeild 20+g of pale yellow crystaline product no oxidation seen at all. Magnetic stirring is awsome, even though I didn' t have it at the end, I don' t think it' s as critical at the end though, at least from an oxidation perspective. Maybe poor end stirring is causing me a problem with reaction completion.
I have been doing a little looking around at info on nitro derivatives of salicylic acid and I believe what I have predominantly is trinitro-m-phenol-sulphonic acid. It is the fourth benzene ring diagram on the link I gave up this page some. From what I can read it appears to be kind of a natural stopping point for the nitration of salicylic acid, however of course as it says in the link if forced more the end product will be Picric Acid. I just need to figure out how to apply a little more force. I have another link here that has a method to manufacture and good/small description of trinitro-m-phenol-sulphonic acid.
http://www.ias.ac.in/jarch/proca/3/00000259.pdf
(more than half the way down pg)
m.p. 105C
pale yellow (very pale yellow)
hygroscopic (mine is very, even after carfully washing off H2SO4 several times and recrysalizing from water then drying in oven at between 60-80C)
The description seems like a good description of the crap I have on a plate right now. Does this seem right to you? If so any ideas as to why I can' t seem to break those last bonds and get true TNP?
note:I was wrong to say very hygroscopic, it is not deliquecent or anything, it just never realy dries out no matter what. Also solubility of this stuff appears at least close to what it should be for Picric Acid. Maybe a small quantity of this hygroscopic, poor explosive intermediate to Picric Acid could cause the characteristics observed in my sample? Other people at different times have talked about unexplained hygroscopicity even sometimes with fairly descent yields I believe.

[Edited on 10-6-2009 by Hennig Brand]

[Edited on 10-6-2009 by Hennig Brand]
View user's profile View All Posts By User
Hennig Brand
International Hazard
*****




Posts: 1284
Registered: 7-6-2009
Member Is Offline

Mood: No Mood

[*] posted on 10-6-2009 at 08:12


On more careful observation of my product form ASA after recrystalization it appears that my yeild has dimminished more than it should have for pure picric acid. I used about 300mL of boiling water to put my 20g in solution(should have been more patient with additions probably would have taken less H2O).My yeild after letting stand for 24 hoursin solution, then vaccum filtering and drying with moderate convection heat was only about 14g. I think this at least 2g more than I should have lost if fairly pure sample(I know losses can vary bassed on impurities but this seems excessive)
The hygroscopic nature of my product would indicate greater solubility than a non hygroscopic sample(I think). If it is the trinitro-phenol sulphonic acid then this would explain a lot as the solubility in the 40% H2SO4 solution after dilution at the end of nitration would not be as great as it would be in the water during purification(I think). The problems with losses due to nitro-sulpho-phenol are disscussed a little in a couple places in Urbanki book one section on manufacture of picric acid. A couple methods in that section report loses of from 20-30%(of theoretical)they partly attributed these losses to the inability to completely convert all of the nitro-sulpho-phenol to Picric Acid(oxidation losses also accounted for some,and lower nitro phenols). This was with very refined processes, and expert procurment and care of reactants. I believe lessons may be learned from this that can be used when dealing with the trinitro-phenol-sulphonic acid when going from ASA. Is this nitro-sulpho as easy to deal with as the phenol version? (I would also like to point out that if my 20g yeild did have much nitro-sulpho in it, due to bonded water in that molecule(as illustrated in link on last post), then my mass would have been reading artificialy high. For every mole there is 4 moles of water bound according to that.
Since I now have probably 60+g Picric + Sulpho (if correct), it could probably be nitrated further to nearly pure Picric Acid, if I could find or figure out a process. As purification seems impractical, unless I am just lacking techniques for purification. At some point, as pointed out by others purifications becomes difficult, and sometimes impractical.(good solid nitration should be primary goal,most economic way!)
There may be other routes to Picric Acid from ASA but I believe this to be the usual. But there is a lot I don' t know. Any insite appreciated.:)

7 hours later
note:I have been making kind of a mess of this, the ideas are there but there are inconsistencies and mistakes through the last page. I believe that I have solved my problems or at least figured out what they are. I have more information, but rather than hammer through with fuzzy thinking and mistakes, I am going to wait do some reading, experimenting and writting things down. Then I will have a better chance of writting something concise and to the point.
I think we may be able to get a good handle on the personality differences between the ASA and phenol routes(pros, cons, etc).

[Edited on 10-6-2009 by Hennig Brand]

[Edited on 10-6-2009 by Hennig Brand]
View user's profile View All Posts By User
Hennig Brand
International Hazard
*****




Posts: 1284
Registered: 7-6-2009
Member Is Offline

Mood: No Mood

[*] posted on 11-6-2009 at 06:15


I know I have been blabing a lot, I promise to relax a bit but I have something to point out.

ASA(C9H8O4)molecular mass-180.157
Salicylic Acid(C7H6O3)-138.12
phenol(C6H5OH)-94.11

Regardless of how one believes the reaction from phenol to proceed(maybe in different ways at hte same time in varying amounts), there will be one mole of water produced for every mole of ASA turned into phenol(as well as one of CO2, and what looks to be two extra carbons?)
Most of way down in this link has good diagrams of ASA to salicylic and to phenol(even though I don' t know if I agree with everything stated on the page completely).
http://www.crscientific.com/article-aspirin.html

So 94+18=112
18 over 112=0.16
times 100=16% H2O
Or exactly double the water produced than what my phenol USP hyrate fused liquid(92%phenol/8%water) has in it. There may be other sources of water peculiar to this reaction(oxidation,other), I don' t know yet.
So water is a much bigger concern with the ASA route, which explains somethings I quess.
This coupled with a greater need to achieve greater reaction completion with the ASA route because of more problematic intermediates(postulated by me), makes this a blow to the ASA route. I still have many reasons for liking this route and will continue to struggle with it.

Just a thought, I wonder if the water could or is removed during sulphonation of ASA. The reason I ask is the mole of water is broken off whether one goes to sulph-phenol or sulpho-salicylic acid. The max temp I have seen for a sulphonation in Picric Acid synthesis is 150C I believe, but I realy don' t have a working knowledge of the limitations. A look at a vapor pressure chart for sulfuric acid mixtures might give some insite as to whats possible(as well as decomp info for sulpho products in solution).?
The other thing is that the carbon dioxide is not broken off untill the conversion to a phenol. I have seen no release of CO2 during sulphonation, but then again maybe I wouldn' t see it?
If anyone is interested I believe there are procedures for precipitating, separating and analysing the product of a solphonation. I have seen one procedure for sulpho-phenol and sulpho-salicylic acid I believe, but I am not exactly sure in what book right now. This might be a way of definitively finding out about the sulphonation process, under different conditions. It might be rewarding for someone.

[Edited on 11-6-2009 by Hennig Brand]

[Edited on 11-6-2009 by Hennig Brand]
View user's profile View All Posts By User
grndpndr
National Hazard
****




Posts: 508
Registered: 9-7-2006
Member Is Offline

Mood: No Mood

[*] posted on 11-6-2009 at 17:23



Im not a chemist and I dont play one on TV.Just a fascinated layman,intrigued by all the aspects of energetic materials and thier uses including the odd uses such a explosive welding of dissimilar metals.The synthesis, ballistics ,shockwave formation and reactions of monroe and miznay chardin effects
theoretical and practical having used weapons that utilized these principles in the military

I did see some interesting info that may be of import with your phenol synthesis and low yields.From Davis, 'Chemistry of Powder and Explosives',pg 159 "..oversulphonation and the loss of unconverted water soluble nitrated sulfiuric acids in the mother liqours...Unless carefully regulated the production of phenol is accompanied by losses,either from oxidation of the material with production of red fumes which represent a loss of fixed nitrogen..."

IIRC you let the synthesis cool to room temp before the addition of the nitrating salts?All Ive read indicates this is not the correct way to do the synthesis the explanation of why is on page 3 of this thread ! The first post on that page
by Roscoe Bodine! In fact all of MR Bodines posts are informative and as accurate as any youll find. Read his posts and Im sure many if not all of your questions would be amswered far better than anything I could help you with or a good portion of the members for that matter.

I havent used phenol myself or seen it used but Davis's book
contains a claim by Olsen and Goldstien that they were able to develop a process by which 100gr of phenol were nitrated to yield 220gr of picric acid!Although phenol is not an easily available over the counter precursor as is ASA which is far cheaper particularly as youve mentioned as a pure powder from a vet or ranchers supply co.In fact the majority of available imp.picric acid synthesis use ASA purifyed from aspirin tablets via methanol or HEET an easily available product here used to prevent gasline freeze/remove water from the fuel tank.Take heart, ive read that picric acid is one of the easiest high nitrates to synthesise.Soon youll wonder how and why you thought it was a difficult synthesis.

Im very interested in how your magnetic stirrer was improvised. Perhaps you would be kind enough to PM me with the basics. Regards grndpndr

[Edited on 12-6-2009 by grndpndr]

[Edited on 12-6-2009 by grndpndr]
View user's profile View All Posts By User
Hennig Brand
International Hazard
*****




Posts: 1284
Registered: 7-6-2009
Member Is Offline

Mood: No Mood

[*] posted on 12-6-2009 at 09:45


Thank you for the information, the stuff in chemistry of powder and explosives is good stuff and I will keep it in mind. Actualy I was up till 2a.m. this morning doing another ASA go and I used only a two hour sulphonation, mostly out of lazyness, but after reading your post I am glad I did. I was also much more careful of the water, I verified that my H2SO4 was of at least 95% purity and I used a little less of my nitric acid(I thought originaly that by adding it in excess that I was doing the reaction a favor, but actualy once fully aware of water issue, I realized that by adding more than needed I was actualy adding more water to the mix.:( My nitric is measured at 90-92% by density, so that 8-10% water, but another thing it is kinda yellow cause I didn' t use vaccum or much gentle heat when distilling(in a rush). Dissolved nitrogen oxides can realy through off a density reading. e.g. in book 8 of encyclopedia of explosives and related items, I believe(same book that Picric Acid is in, n before p), it has some densities for different grades of nitric acid. White fumming 98% I believe is around 1.505 s.d., and the red fuming can be over1.59. Big difference, although I am unsure of all the implications. With practical knowledge a person could probably just look at the shade of the acid and tell a lot(I think). If my density was taken and used on white nitric tables what does that mean for my actual water content?
My yeild from my experiment was about 16g from 18g of ASA after recrystalization, which is a much better yield than last time. The reaction went totaly different. Color changes where very sharp. At first it was of course a purply, brown, blue or somthing then it went realy red, and after heating light again.(I think it went yellow but because of brown dye, (yellow plus brown does give a lighter brown I would think?) The product crystalized in beautiful large needles of a little darker yellow than my last experiment. It filtered and dried very easily(pure joy to work with)
When one adds Sodium Nitrate to H2SO4 there is no water produced (NANO3+H2SO4=NaHSO4+HNO3), to realy replace this one does need a nitric with no water( is this correct). I wonder if the power labs guy actualy tried his synthesis with 70% HNO3 and ASA? He did seem to try and compensate by useing a lot of the acid, but at 70% he is adding a lot of water to. In the future I am going to use HNO3 of strength and purity as good as I can produce. I haven' t gave a sample a whack yet because of torential rain storm all day, but the material looks good.
Rosco Bodine, I never realy known him to work with phenol when making Picric Acid(maybe he did and I didn' t see it). These reaction are not at all the same in their personality. There are similarites but that is as far as it goes. Phenol takes to nitration very easily and as a result water is not nearly as stiffling on the reaction. The end product seems to be quite different because of impurities, although if both went to absolute completion then they would of couse be the same,(pure TNP). Even with small yield the product from phenol seems better than a comparatively larger one from ASA(in my limited experience with phenol,(2 experiments)), however I have no doubt that some on this site can make a product from ASA that rivals any from phenol.
You are right about not letting it cool to much before nitration I believe(reaction seems to need a bit of momentum, several sources say to not let reaction temp dip below 100C during final stage, I presume to mantain this chemical momentum?
I get my pure aspirin very cheap as I have friends at the drug store, or they are at least friendly to my hobby(I am carful to always make my experimenting appear benign). A pound for 12-13$ canadian.
Ah the Monroe effect, I played around with that a bit a couple years ago when looking at home made claymore mines(just educational), cool stuff! I like shaped charges, but have never built one. I have played a little with different tampings and charge configurations though. I' ve made about half a dozen different nitric esters(ethers?) with very limited problems compared to these damn aromatic hydrocarbons.As well as peroxides (HMTD is the best in practise, regardless of what it says on paper, than AP) I also make a lot of my own chemicals(acids, bases, chlorates,metal powders, solvents, etc). I like improvising lab equipment as well, mills, stills, electrolisis cells,heating devices, modified vaccum for chemical use, magnetic stirrer, electronics and other.
I have seen those claims of super high yields with phenol as well, and while I don' t doubt they get it, I have also seen a lot of lab texts quoting yields not that disimilar from mine.
I would gladly tell you about the magnetic stirrer, even tell you how to obtain the parts. Maybe a picture and a discription should go somewhere?

What is PM?, do you mean just put in a post, or is it something else like email.(I don' t do a lot on computer other than look for info)
For starters though go to shroomery.org and look at the section on home made magnetic stirrers, thats where I got the basic idea. I don' t believe they had a speed control on theirs they just made it a slow managable speed by choice of power supply. A variable current or voltage power supply would be best, which is what I use(before chemistry I did a lot of home brew electronics). A small power supply from a model train set is variable output they usualy put out 16 volts or so which is over the 12volt specs on the fan motors, however as long as the output is not left wide open the current would not be enough to hurt the motor I wouldn' t think. Some small DC motors are tough as nails anyway, and this one has its very own worlds largest cooling fan! Distance from the fan motor to the attachment of the magnet will have to be determined through trial and error as the magnet strength and the distance will determine whether or not the magnetic field locks up the motor, or impeeds its function at low current(speed). Some sort of spacer will probably be in order. I used some PVC pipe the same size as the hub the blades of the fan attach to. The magnet could be held above the motor when running to see the effect on it at different distances and different speeds. The make spacer desired length. I ground a groove to seat the magnet in the top of the pipe, and hot melt glued it in place and also to the fan hub. A frame was made out of wood and small nails(as well as the casing piece the fan was attched to on the PS).The fan was taken off and put back on the opposite side so sides faced up, on yours it may be already right. The beaker with pill and some water can be held above the running fan/magnet at different speeds and heights to see what works best with your magnets. Remember as you get further away from a magnet the force becomes less, but also the lines of force change direction(my Dad told me this, he was a bit of a pyro in the fifties, I found some chems from the fifties, when he was a teenager, H2SO4, powdered metal). I got my magnet out of one of those perpetual flashlight, you know you shake like hell and get a little bit of light for a short time. Any way they are pretty cheap some times(full size name brand one for 7$ I think, 1/2 price). The magnet in them I believe is a rare earth magnet, strong, strong magnet. Probably too strong, but it is what I had. It is also not nearly as long as my pill(stir-bar), with gives me less torque, but the magnet is so strong I can hold the beaker away above and it works fine. To strong a magnet may cause extra pull and friction, but unless you are worried about burning out the motor or power supply, if for what-ever reason they are a little too weak, I wouldn' t worry about a little extra power consumtion.
I think it can be turned into a hot plate stirrer as well but I am still toying with it. I am looking at an old stainless electric skillet or something like that in my junk pile. Good stainless too, the kind a magnet don' t stick to! If the stirrer could be placed underneath this or something like this(maybe made of something else) and didn' t interfere with the magnetic field, I think it could work. The skillet/frying pan thing could be accuratly controlled with a big light dimmer, or something better and more professional if you wish.(something maybe with feed-back so you don' t have to be always adjusting temp a little?) Either water or oil would fill the pan, maybe evan sand depending on use. We will see how it goes.
I don 't know if all computer fans are DC but they must be. Avoid AC, it is very difficult to control unless the motor has brushes. Most times fancy power electronics are employed to change frequency of AC to moter(expensive). Some AC motors, like in some ceiling fans may be speed controlled with a light dimmer, but they are the anomoly, and are the appropriate power rating for the dimmer.
A DC speed controller can also be built, but most should not need to be reduced to that(unless they want).


[Edited on 12-6-2009 by Hennig Brand]

[Edited on 12-6-2009 by Hennig Brand]
View user's profile View All Posts By User
Hennig Brand
International Hazard
*****




Posts: 1284
Registered: 7-6-2009
Member Is Offline

Mood: No Mood

[*] posted on 14-6-2009 at 04:19


I just wanted to say that I finaly have success with ASA route(although in small final yield). The last ASA experiment I did I told you I had 16g after one recrystalization, well after drying it seemed to melt well, burn well, look well, but it was still quite insensitive. It also seemed to not dry quite as well as it should(indicating presence of sulpho-phenol?). I did one more recrystalization and only collected the first 11g or so that came out of solution on cooling before it dropped much below 40C. I left the rest in the beaker and when it did come out, man what bad looking stuff(I believe floculant is the right word). Anyway this 11g of product dried in oven at 60-80C for hour or so and was tested and it seems to be about the quality of my sample from phenol(easily set of with quick snap of hammer on anvil, with satisfying crack). I need more work on my nitration obviously. As Grndpndr has said the product should probably almost be able to be set off right from the nitration. I think that if I can get a product that is decent after one recrystalization I would be happy though, which would also afford a better yeild. With more care to keep both acids strength at start of nitration up over 95%, the last stage of nitration would be much quicker, and would go more to completion before petering out. With even what I thought was a small amount of water the final stage of nitration goes on for hours, and even then never realy seems to complete. 11g from 18g of ASA, nothing to brag about, but I have a sample that is dry and a high concentration of TNP. For now I am happy. :)

Final note, when a nitration is such that it goes on for hours at 120C or near that, it is distilling of your precious nitric acid, leaving behind a mix with a higher concentration of water, and maybe even not enough HNO3 to do a complete job of final stage nitration.

Does anyone know if I could be damaging my Picric Acid in anyway by drying it in the oven at less than 80C? If still significantly damp when it goes in it may change the crystal density and stuff I think but I don' t know for sure. I don' t think it would change it chemicaly though(TNP is pretty tuff at those temperatures I think)
[Edited on 14-6-2009 by Hennig Brand]

[Edited on 14-6-2009 by Hennig Brand]
View user's profile View All Posts By User
1281371269
Hazard to Others
***




Posts: 312
Registered: 15-5-2009
Member Is Offline


[*] posted on 14-6-2009 at 10:26


I followed the instructions given in the second post of this thread (only using a tenth of all the amounts) and everything went fine, correct colour changes, until the last step - getting out the picric acid crystals.
I realised that what the step described was basically adding water and then cooling and filtering, so I added the water (a great amount more than instructed) cooled, filtered...and got a nice yellow / orange filtrate. I then tried boiling this down a little and then recooling, to no effect.
I did notice that on heating it changed from orange to more of a light yellow colour. How can I get the crystals out of the solution? Would boiling all the liquid away work or would there be a risk of detonation?
View user's profile View All Posts By User
entropy51
Gone, but not forgotten
*****




Posts: 1612
Registered: 30-5-2009
Member Is Offline

Mood: Fissile

[*] posted on 14-6-2009 at 11:42


Mossydie,

The Merck Index says picric can detonate at over 300 C, way above the temperature of boiling water, but the stuff crystallizing on the walls of the heating vessel might be overheated without good heat control, for example over an open flame or a hot stove.

Just start over!

Best not to improvise the first time you try a prep.
View user's profile View All Posts By User
1281371269
Hazard to Others
***




Posts: 312
Registered: 15-5-2009
Member Is Offline


[*] posted on 14-6-2009 at 11:48


I'd also have to boil off the H2SO4 that was in there...but it does seem a little bit of a waste :( Ahh well.
View user's profile View All Posts By User
hissingnoise
International Hazard
*****




Posts: 3940
Registered: 26-12-2002
Member Is Offline

Mood: Pulverulescent!

[*] posted on 15-6-2009 at 07:28


You do know that H2SO4 boils @ ~338*C?
View user's profile View All Posts By User
1281371269
Hazard to Others
***




Posts: 312
Registered: 15-5-2009
Member Is Offline


[*] posted on 15-6-2009 at 11:27


Yes, that was my point!
I should have made it clearer. Boiling off the impurities is certainly a bad idea. I wonder if I could use the liquid acid to make lead picrate?
Adding it to lead monoxide should work but Lead Picrate is also water soluble so I wouldn't really have achieved anything unless it has a much higher detonation temperature (aka critical temperature?).
[Edited on 15-6-2009 by Mossydie]

[Edited on 15-6-2009 by Mossydie]
View user's profile View All Posts By User
grndpndr
National Hazard
****




Posts: 508
Registered: 9-7-2006
Member Is Offline

Mood: No Mood

[*] posted on 15-6-2009 at 12:52


lead picrates extremely sensitive and very likely to detonate
at the slightest whim.I am very likely overstating the instability of lead picrate but for the amounts youd be needing a few grams of TNP and a few grams 'litharge' lead oxide/monoxide its not worth the risk.FWIW I was thinking along gththe same lines as TNP is an excellent booster in a composite cap and from waht Im told is excellent with MF/TNP
1/2-1gr/2-4gr TNP engineer grade cap perhaps?

Since so far marginally successful synthesis have you noted the temp at which your sulphonating then nitrating
your TNP? Ive recovered some old notes and unless im missing something the temps your using are double what ive ever heard used for asa- H2SO4/Nitrate salts!

70-80c H2SO4 sulphonating temperature lasting until the mixture turns black than perhaps another 1/2 hr-3/4 hour further at the same temperature.

Remove from heat! cool to 30- 50c then begin to add nitrate salts slowly,temp shouldnt rise above 70-80c causing minimal nitrous dioxide fumes,which will only waste the nitrates.A reddish hue should begin to be evident.After all the nitrates have been added let the synthesis cool to room temp the yellow cast should be very evident.

Crash the synthesis in a ice cube /water mix about
2x the amt of the synthesis when the ice has melted
filter off the crystals.Some save the liquor from the synthesis but personally I havent seen folks have much luck getting additional picric acid OT a few grs.hardly worth the effort IMHO

Take the filtered crystals and add them to about 200ml boiling water per 40 grs asa from starting synthesis again cool the remaining hot mix in a fridge or freezer if anxious t until the TNP again recrystalizes
This is Supposed to be a very pure trinitrophenol sufficient for the great majority of uses including long storage with 10-30%water.

Acetone is also mentioned as a final recrystalizing purification method but i do think Its rarely needed.Given good clean precursors the water crashed TNP should be at least a good tech+ grade more likely closer to a reagent grade.

Ive seen it tested by putting a pinch in a spoon and heating with a common lighter waiting until it turns black/bubbles then geflagrates with a distinct pop.Others say over 80%TNP will detonate from a hammer blow with a few small pinches wrapped in paper towel or AL foil on an anvil or another heavy piece of steel.It seems to me MNP, DNP should
be removed from the TNP with the recrystalization as well as be visible in the water assuming anys present.
Regards

You can dry the crystals in the oven at its lowest heat with the door ajar at most 70c but Id prefer the sun or a dessicator.Im going to try a jerky making machine that was given to me.Moderate heat along with air circulation.

Theres also a similar method for recrystalization /purifying using acetone but no one has ever mentioned its superiority.

[Edited on 15-6-2009 by grndpndr]

[Edited on 15-6-2009 by grndpndr]
View user's profile View All Posts By User
1281371269
Hazard to Others
***




Posts: 312
Registered: 15-5-2009
Member Is Offline


[*] posted on 15-6-2009 at 13:03


This is more or less what I did right up until adding the ice when I found another member of the household had prepared a crushed ice smoothie :mad: . I will retry the synth at some point although I'm out of MeOH atm - my choice for removing the ASA from the tablets because it's cheap and easy to get hold of although a bit annoying because I had to evaporate it in a place devoid of any civilisation and in a good breeze. I could have used Meths but I wanted the colour changes to be as evident as possible, it being my first attempt at the synth and all, and the purple dye would have ruined that.
View user's profile View All Posts By User
grndpndr
National Hazard
****




Posts: 508
Registered: 9-7-2006
Member Is Offline

Mood: No Mood

[*] posted on 15-6-2009 at 14:15


A lead picrate synthesis also reccomends heating the just synthesised lead picrate @ 80c for 2 hours to convert it to pure lead picrate rather than a monohydrate.Supposedly lessens sensitivity.It vseems far more shock msensitive than friction sensitive although charts will need to be consulted.

I didnt know youd found the correct times and temps.Earlier posts indicated very high synthesis temps.
That part is fine but reading the synthesis by color change and other reactions seems equally important. You will be successful with the whole firing train Im sure, Lead picrate/TNP/Ammonium picrate exp D.

The real disadvantages are many however toxicity and a permanent dye being a couple of many only melt /mix Ive run across is trimonite MNN/TNP 7048 @1.6gr cc3
View user's profile View All Posts By User
1281371269
Hazard to Others
***




Posts: 312
Registered: 15-5-2009
Member Is Offline


[*] posted on 15-6-2009 at 15:23


Yeah, I should buy some Iso propyl or ferment some EtOH really, MeOH scares me even if it would take quite a large dose to do real damage. Shoving some yeast in a saturated sugar solution, leaving a few weeks and then distilling should do the job...sounds pretty easy. PhZero also suggested home brand mouthwash as a cheap, if not totally pure, EtOH source.
But I digress,
I may have also added the KNO3 too fast - the instructions said '<1g / minute whilst stirring'. With some better equipment and an automatic stirrer it could be added constantly and very slowly whilst I stayed totally out of the way. As it was I got some nasty NOx fumes given off and had to hold my breath for a few seconds, then move away, take a gulp of air, move back in. Not totally practical. I'm in the middle of building myself a stirrer so that one should be sorted before my next attempt.
I don't even have a thermometer ( :O, I know) so I was just estimating on temperatures using a water bath and a vague scale on the hot plate. Is it important that they be very accurate?
View user's profile View All Posts By User
Hennig Brand
International Hazard
*****




Posts: 1284
Registered: 7-6-2009
Member Is Offline

Mood: No Mood

[*] posted on 16-6-2009 at 04:55


If you shove regular yeast in a saturated sugar solution you will just kill them off. Also without some nutrients to aid the yeasts growth and multiplication(budding) they will die out very quickly and you will get little to no alcohol. The max percent sugar concentration that regular yeasts can handle(with out croaking) is a concentration that yeilds less than 15% alcohol and maybe more like 13% for some yeasts or if yeast are stressed for whatever reason. Considering that water can dissolve about 2 parts of sugar to one of itself(which is very thick and syropy), this is many times more than what any yeast will handle. Also if using refined white sugar nutrients must be added or the yeast will die with little alcohol production. There are prepagaged yeast plus nutrient mixes bought from brew shops that will alow one to easily make ethanol from pure refined sugar and water without having to know about nutrients.

[Edited on 16-6-2009 by Hennig Brand]
View user's profile View All Posts By User
 Pages:  1  ..  8    10    12  ..  31

  Go To Top