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Intergalactic_Captain
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Need info on KClO4 propellants
Not sure if this belongs here or in miscellaneous, so mods take note and move if necessary...
Anyways, I'm in need of a relatively cheap, high-impulse fuel for 3/4-1" ID x 4-8" long core-burning rocket engines. NH4ClO4 composites seem to be
the propellant of choice for high-impulse engines, but cost constraints are leaning me towards KClO4 instead.
I have been able to find surprisingly little information on this material as an oxidizer...Short of early JATO development, there is not much info out
there and even less on fuels other than asphalt. Urbanski gave a few references that I need to check, but a look at their titles doesn't seem to
indicate that they'll help me out.
One of the things I'm considering is a high-melting paraffin wax as a fuel, but the only thing I've been able to find is NASA reports on its use in
hybrid LOX rockets. Another possibility is epoxy resin, though this would push me into the "rediculously expensive experiment" range.
So, anyone have any references and/or first-hand experience on the use of KClO4 as a rocket oxidizer? Note, I am well aware of whistle-mix and would
rather avoid it...Not that it's particularly expensive, just that it's not really suited for nozzled rockets and happens to "whistle" rather than
"whoosh."
If you see me running, try to keep up.
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MadHatter
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NH4ClO4
KClO4 works well with many fuels, except powdered metals. I would suggest trying to
prepare NH4ClO4 from either sodium(recommended) or potassium perchlorate.
Again, KClO4 will work with a lot of fuels but the "whistlers", benzoates, are my favorites.
I do prefer them over the sucrose/KNO3 fuels because of their increased performance
and their distinctive sound. But to each his/her own. Good luck on your fuel search.
It's really a matter of experimentation and what your goals are. BTW, wax would make
a good fuel for your application. I can't say that I've seen references on it though. This
is just from personal experience.
From opening of NCIS New Orleans - It goes a BOOM ! BOOM ! BOOM ! MUHAHAHAHAHAHAHA !
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chemkid
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How would one either go about aquring or synthesizing pottasium or sodium perchlorate? Furthermore, what sort of safety measures would one take with
such oxidizers?
chemkid
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Xenoid
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| Quote: | Originally posted by chemkid
How would one either go about aquring or synthesizing pottasium or sodium perchlorate? |
Hmmmm... This endeavor seems to be the subject of the most and the longest threads in this forum...
Note: A few perchlorate compositions are given by franklyn in this thread;
http://www.sciencemadness.org/talk/viewthread.php?tid=8746
Regards, Xenoid
[Edited on 17-10-2007 by Xenoid]
[Edited on 17-10-2007 by Xenoid]
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Mr. Wizard
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I remember reading about perchlorate and asphalt pitch being used as a solid rocket fuel in the past. It was mentioned in some amateur rocket book in
the mid 1960s. I think it was called Galcit. I'll leave you to do the searches.
A side note is the DOW Chemical company which got it's start manufacturing Bromine to fight Typhoid in wells, decided to use asphalt covered wood as
containers and cells to make the Chlorine needed to free the Bromine from brine wells. They actually got rich using the products made from the left
over Chlorine.
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Intergalactic_Captain
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Yeah, I checked out the Galcit stuff...Seems to be just KClO4/asphalt. Once the team discovered NH4ClO4, they took off in a different direction
(thiokol and rubber/plastic binders and fuels). I think I'll probably focus on wax - No literature, no patents (at least none since 1976, anyone got
a better searchable database than the USPTO?) - Only thing I can find is posts in various forums hinting that it might work. So, I'm calling this one
- If anyone patents this one before I do, know well that I'm not above hunting you down and hammering your kneecaps in  .
Anyways, I figure wax will probably be slow burning and hard to ignite. Ideas thus far are use of an iron oxide catalyst for enhanced burn rate and
possibly aluminum powder to enhance ignitability. Should the aluminum be too much, I'm considering having a thin layer of al-enhanced fuel in the
core, with the main fuel grain around it... ((({O}))) where () is the main grain, {} is the al-enhanced layer, and O is the hollow core...Should
light easier and spread the flamefront faster, but the pressure spike might lead to CATO's.
Oh, and thanks for the little side note on DOW - I knew about the low-tech bromine thing, but I didn't realize it was the antibacterial market for
chlorine that drove them...I was under the assumption that they were focusing on bromine, not unloading it as a byproduct.
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Mr. Wizard
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They got their start making Bromine for the anti-typhoid market. They used a brine well to get the raw material. To make the Bromine they had to make
Chlorine, they then had excess Chlorine; for which they then developed a market. Even though Chlorine is the most common disinfectant now, then it was
too hard to store and contain. Bromine had the advantage of being a liquid and a few drops down a well would sterilize the water. Now doubt it sold
quickly after a few of your neighbors died of typhoid. Store keepers could keep a shelf of it handy for impulse (panic) buying.
Candle makers have a special tough wax they use on the outside of candles. It almost feels like plastic, but it melts and can be used for candles.
Maybe it would be a better option than plain paraffin wax?
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Intergalactic_Captain
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Ahh...That story makes a bit more sense now.
Any idea what this outer wax is called? I know what you're talking about, just no idea what to search for. I was thinking about using a high-melting
wax, like used by sculptors to make positives for molds. Some of the NASA articles alluded to "hurricane candles," though I'm not exactly sure how a
high-melting wax would have anything to do with the wind resistance of a naked flame...Maybe it just lasts longer than standard paraffin wax. In the
meantime, I've got quite a bit of mason-jar sealing wax, though I'm not sure how well it'll stand up to the temperature of a 3000degC flame.
If you see me running, try to keep up.
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Mr. Wizard
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The wax used by sculptors is most likely the 'lost wax' used in jewelry and denture making. It is very hard. I don't know what the hardened out wax
is called, but it may be an admix called Vybar 103. Any candle makers out there?
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Twospoons
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There's always NH4NO3 with Mg, and a HTPB binder as outlined in this book..
CP Technologies
I've got the book, and it is very detailed with regards to formulating and testing nitrate based propellants. Also covers motor design - but given
the nature of your question you probably know about all this already.
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artem
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| Quote: | Originally posted by Intergalactic_Captain
I have been able to find surprisingly little information on this material as an oxidizer...Short of early JATO development, there is not much info out
there and even less on fuels other than asphalt...
|
There were some references about KClO4 in early solid propellants:
1)ALT-161 (Aerojet jato): KClO4 76%, bitumen(asphalt) 16.8%, oil 7.2%. Jsp=173, d=1.77, u=1.29*P^0.7(mm/s, P -bar)
2)KClO4 76.5%, bitumen 23.5%. Jsp=186(140bar), d=1.77
3)"Basuka": KClO4 76.28%, HPTB 21.94%, castor oil 0.9%,additives 0.48%
4)KClO4, graphite, binder, 8%Ti
KClO4 isn't well enough as a rocket oxidizer (smoke, sensitivity, low Jsp), so it was not used widely. I think, it can be used with any available
binder, and part of the binder can be changed by cheap fuel (C, sugar, etc)
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Bert
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| Quote: | | Originally posted by Intergalactic_CaptainSo, anyone have any references and/or first-hand experience on the use of KClO4 as a rocket
oxidizer? Note, I am well aware of whistle-mix and would rather avoid it...Not that it's particularly expensive, just that it's not really suited for
nozzled rockets and happens to "whistle" rather than "whoosh." |
Steve Laduke has made "hybrid" whistle rockets with the whistle mix de-tuned by the admixture of charcoal and/or other black powder ingredients. They
don't whistle, can be made as cored, choked rockets similar to BP configuration but with considerably higher specific impulse. There was an article in
the PGI bulletin recently, and Rich Wolter makes tooling for these motors.
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dann2
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Hello,
Not too well up in the rocket fuel business myself.
The Galsic was used (amongst other places) in JATO units.
(Jet Assisted Take Off). It would be more correct to have called it rocked assisted take off but back in thosed days rockets were referred to as jets.
I guess the jet engine was still in its infancy.
The JATO units were rockets strapped to planes. Theses rockets worked at hugh pressure and the walls of the rockets were very thick (and heavy). The
empty rocket motors were dumped at the end of the runway (or shortly after). The thick walls/heavy containers suited the application as the rocket was
being asked to push only.
What I am trying to say is: I think K. Perchlorate suits very high pressure applications, not too sure though.
I have a formula somewhere that describes using Bakelite (Phenyl Formaldehyde) + Perchlorates as a fuel. The whole thing is fairly easy to make. Will
dig it up. I think it was end burning. East to pour and solid setting.
Wax:
Regarding wax as a fuel I heard of a guy who had good success using it with K. Chlorate (He probably did not have Perchlorate) in small pryo tech.
rockets. Endburning.
He melted the wax and Chlorate. I believe this is fairly safe with wax.
An idea I have had going around around in my head for a long time for using wax as fuel is this:
In order to avoid having to melt the wax, ball mill it.
I would hope that wax would ball mill successfully if put into a ball mill (huh!) and then the ball mill but into a deep freeze.
The hope being that the wax would be brittle enough at this temp. to ball mill into a fine powder.
This could then be mixed at low temp. with the oxidizer and squeezed/ pressed into motor. Heating to approx 50C would then bind the lot.
Might work, might not.
Dann2
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dann2
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Phonol-Formaldehyde + KClOx
Hello,
A Bakelite + KClOx propellent.
Making the resol is relatively easy but if you want to make this king of propellent on a regular basis you need some sort of Vacuum pump
+ chamber and heater (inside the vacuum chamber). It is however possible to make a sstisfactory resol without a vacuum system but the resol takes a
lot
longer to cure.
Note Phenol and Formaldehyde are poisonous and this procecure should be carried out in the open. Once the initial reaction is over and the syrupy
stage is reached then the stuff is relatively harmless (apart from flammability).
Method
Add 20g of Phenol and 0.5ml of 40% NaOH solution to 40ml of 37% aqueous Formaldehyde solution (Formalin). Bring to the boil and boil untill the
liquid
becomes noticably thicker (typically in the order of 10 minutes). If you stop too soon it will take forever to cure the resin, if you wait too long it
will beocme too
viscous to mix with the oxidizer (like toffee) or even become fully cured in whatever vessel you were boiling it in. You might be able to salvage it
with alcohol.
The resol is removed from the heat and 108g of KClO4 or 125g KClO3 is stirred in. The resultant is poured or pressed into a mold/casing. Try your
utmost
to get rid of bubbles at this stage. The grain is cured by placing
it in an oven at around 50C or so for about 12-24 hours. The temperature is slowly increased untill the resin sets rock hard at a final temperature
of 120C or so. <BR>
If you increase the temperature too quick big bubbles will form in the grain.. The first cool part is mostly to allow excess water to evaporate., the
actual curing
takes place at the higher temperatures. A resol that has been dried in a vacuum can be cured somewhat faster.
Never tried the above propellent myself BTW.
Dann2
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Boomer
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After "re-inventing" candy propellant for a science fair project around 1980 (it was known but not to us), we upgraded to NaClO3 (reX'ed from
weedkiller, 2 Dollars per kilogram at the drug store - good old times). There was no way we would melt-cast chlorate/sugar, we knew what a kilo did to
a fire extinguisher! (Do that now and you are put away as a terrorist.)
We had little luck with asphalt/oil but were afraid to use only asphalt (tar) since it melted too high for our taste to add a chlorate.
Ended up with 75% chlorate and 15/10% tar/wax, this can be processed in a water bath if you start with the (normal candle-)wax alone. Using only wax
might pose the danger of it melting in bulk, something opaque prevents the heat radiation from penetrating the unburned fuel too far. This was a guess
but we wanted to be safe.
BTW why is epoxy "rediculously expensive"? 15 bucks a kilo, and you need 20% max, i.e. 3 dollars per kilo for the binder, so the oxidizer will most
likely cost you more.
A 3/4" rocket will hardly need 100g fuel, which means epoxy for 30 cent!
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dann2
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Hello,
Careful with the tar/asphalt. I think it is frowned upon (a no no) with Chlorate.
Dann2
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Twospoons
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The evil thing about epoxy is the exothermic cure. A cupful of laminating epoxy will all but catch fire as it cures. (Yes, I've tried it  ) You need the slow cure type, used for potting.
Urethane could be a possibility, its a cold cure.
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DeAdFX
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You could try KClO4/PVC/Hexamine/Plasticizer like an ester. Find some Gorilla glue. It contains 85/15 solvent/PVC resin. You could try other types
of PVC cements as they contain various combustible resins like polyester or Acrylic Butadiene styrene (ABS) resin. I am pretty certain they will dry
up like a rock so a plasticizer would be an excellent idea.
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Bert
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Gorilla glue is a urethane and cyanoacrylate mix AFAIK.
http://gorillaglue.com/UserFiles/MSDS%20Stronger%20Faster%20...
You don't want a grain full of bubbles, unless you WANT to have a CATO. Gorilla glue foams as it cures...
You don't want any type of volatile that leaves the fuel as it cures, causing shrinking and leading to voids- CATO again.
You might want to check out GE silicone sealer. Several have made rockets with this, as well as go getter type stars.
Or you could bite the bullet and go find some HTPB or PBAN.
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halogen
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"You don't want a grain full of bubbles, unless you WANT to have a CATO. Gorilla glue foams as it cures..."
And a good deal at that.
LDPE (Low Density PolyEthylene) might be a possibility. Melting point is 120*C, and it is apparently available as 'six-pack soda can rings'. This
looks like a useable material, though I can see no reason wax shouldn't work. The only advantages, if any, of LDPE are that while one normally would
buy wax, one can rummage in the garbage/recycling receptacle, and that LDPE would be more standardised as to exact composition.
In either case, additives are your friend. Wax melts easily, which might cause some difficulties in ignition, and during flight, possibly warping your
core, a bad thing. Here, perhaps lampblack or such would be advisable. To aid combustion, and raise the internal heat, a bit of aluminium is a
possibility (though not too much, mind you). Also, a catalyst such as very fine Fe2O3 is advisable.
F. de Lalande and M. Prud'homme showed that a mixture of boric oxide and sodium chloride is decomposed in a stream of dry air or oxygen at a red heat
with the evolution of chlorine.
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Microtek
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I experimented with LDPE fuel/binder with KClO4 some time ago. The propellant was very energetic, but quite hard to process. I used Fe2O3 as catalyst.
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halogen
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Do you recall any particular percentages?
EDIT 'particular' has an 'i' in it...
[Edited on 28-10-2007 by halogen]
F. de Lalande and M. Prud'homme showed that a mixture of boric oxide and sodium chloride is decomposed in a stream of dry air or oxygen at a red heat
with the evolution of chlorine.
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Microtek
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I just used enough KClO4 to oxidize the carbon content of PE to equal parts CO and CO2. I chose this mix because it gives good results with candy
propellants (the rule about enough oxygen to produce equal parts CO and CO2, that is). Afterwards I just added a pinch of Fe2O3 to the finely powdered
KClO4. The LDPE I used was in the shape of PE-film.
I made a lamellar wafer consisting of alternating layers of PE-film and oxidizer/catalyst. Then I heated it on a hot-plate and kneaded it until
uniform. Finally it was loaded into a die to cool and solidify.
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halogen
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Sorry for the bombardment of questions, but I'm thinking of trying this one. If you can't recall, that's perfectly fine.
Did the batch size make any difference (this actually matters as I was surprised to discover with another mixture)?
What temperature (approx of course) at and for how long did you heat it?
What were its solid properties (i.e. how hard was it)?
F. de Lalande and M. Prud'homme showed that a mixture of boric oxide and sodium chloride is decomposed in a stream of dry air or oxygen at a red heat
with the evolution of chlorine.
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Microtek
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The ratio was what I wrote in the above post:
2 (CH2)n + 1.25 KClO4 --> 1.25 KCl + CO + CO2 + H2O
Meaning 28 g PE to 173 g KClO4.
I only made one batch and that was very small; in the order of 5 g. As for temperature, well my hot-plate is actually an iron (as in the household
appliance) and doesn't list temperatures. But since PE melts at around 120 C I would guess that I heated it to maybe 150 C. Then I just kneaded it on
the hot-plate using a stainless steel spoon until quite uniform. Due to the high solids load (86%) the mix is very stiff when molten, so you can't
actually stir it. Instead you press the mix into a flat sheet with the spoon and then fold it over a few times, then flatten it again for however many
times it takes. Maybe it would be easier if the batch was much bigger.
When it cools off, it gets very firm (much like solid PE in fact) but a little more crumbly than pure plastic.
BTW, I tried this type of binder in combination with nitramine explosives (HMX mostly but also some RDX) and it really works quite well as PBX-type
charges.
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