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blogfast25
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Quote: Originally posted by deltaH  |
However, the iron soap is changing matters, since the ferric linolate is runny, it might be castable as is. Anyhow, early days and lots of work in
store. |
But it still contains loads of water too. Even if, as I assume, you started from pure ferric nitrate nonahydrate (and not a solution of it). So what
will it be like when it's been dried?
Couldn't castability be regulated with small additions of a highly oxidisable oil like light mineral (paraffinic) oil?
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deltaH
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Praxichys mentioned using xylenes as a diluent on page 2. I'm not a fan of the paraffins, I think they will slow down the burn as
Bert mentions somewhere thereabouts too.
Yes, the water may be a problem, particularly for the baking stage, as it might mushroom out the cast.
I'm thinking it might be carefully heat treated first to remove the water... like one would normally dry an oil. It is a semi-liquid after all, should
be no problem to heat to around 100°C and hold for 30 minutes. I don't think it will froth because it seems to behave more like a hydrocarbon and
less like a soap. I think it doesn't have the right shape to be a surfactant.
In fact, I'm probably going to boil down this mess I made to isolate everything and pray it doesn't polymerise, instead of sticking it in the freezer.
It's going to contain sodium nitrate, but I'm adding more later anyhow and I know how much is in there which is what really matters 
[Edited on 22-3-2015 by deltaH]
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blogfast25
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| Quote: Originally posted by Bert | From personal experience, flammable oils, either of organic or mineral origin in VERY small percentages will greatly slow a solid fuel or other
pyrotechnic mixture-
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Hmmm... the backbone of your linolenic acid is quite paraffinic too!
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aga
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Sorry if this is not directly releated to the OP, yet i would like to succeed in making Factice that can be removed from a pot as lump, rather than
having beakers full of sticky brown goop.
Which Oil stands the best chance of success ?
Linseed ?
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blogfast25
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This post has the unsaturation levels of several oils:
http://www.sciencemadness.org/talk/viewthread.php?tid=61792&...
Linseed oil should work well because of the high content of polyunsaturated fatty acids (linolenic acid in this case). It's also fairly OTC.
In the *.pdf linked to above (Factice from Oil Mixtures, Selim M. Erhan and Robert Kleiman) recommends 20 parts of sulphur per hundred parts of oil,
cook for 40 minutes at 180 C.
[Edited on 22-3-2015 by blogfast25]
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aga
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Sorry. I missed that.
Thanks for the reference.
I'll get some Linseed oil and hopefully make a beaker less dirty next time.
Wife wasn't too happy about the plates i used, and as a bonus, i was so engrossed that i forgot about the new kettle, which melted onto the gas hob
for an hour or two.
Thankfully the plastics were mostly Carbon by the time i went inside and noticed.
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deltaH
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Yes if you want rubbery stuff, you have to use a so-called 'drying oil', the most common OTC one is linseed, also called flax seed oil in health shops
(though very pricey from there). Another one that is available from selected hardware store is Tung oil or 'china wood oil', that's probably the best,
80+% alpha-eleosteric acid (another triply unsaturated fatty acid).
I've said it before and I'll say it again, if an oil is high in polyunsaturated, it's not necessarily good for this, because linoleic acid for example
(found abundantly in sunflower oil), with two double bonds IS a polyunsaturated, but it sucks at making factice, you really need an oil high in
linolenic acid or another triply unsaturated fatty acid, specifically.
I strongly advise making soaps from the oils first and ditching the glycerine, I have a strong suspicion that it's the main culprit for making the
severest stinks by way of volatile thiols. Also the making of a soap also reduces the volatility of the fatty acid, particularly with Mg and Ca, this
also helps.
[Edited on 22-3-2015 by deltaH]
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blogfast25
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In the *.pdf linked to somewhere above (Factice from Oil Mixtures, Selim M. Erhan and Robert Kleiman) recommends 20 parts (!) of sulphur per 100 parts
of oil, cook for 40 minutes at 180 C.
[Edited on 22-3-2015 by blogfast25]
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aga
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OK.
So more sunflower oil, saponify, then go for the Factice ?
I feel a bit silly here, as i'm not aiming for what your OP is after, just a solid Factice.
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deltaH
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No not sunflower oil, that doesn't make a rubber.
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deltaH
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Yes saponify linseed oil first with lye, then boil up to dissolve most of the soap, then use magnesium sulfate (Epsom salts) to salt out and produce
the magnesium linolate that you can use to make factice. It should be far less stinky, but that is to be confirmed
[Edited on 22-3-2015 by deltaH]
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blogfast25
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| Quote: Originally posted by deltaH |
I strongly advise making soaps from the oils first and ditching the glycerine, I have a strong suspicion that it's the main culprit for making the
severest stinks by way of volatile thiols. Also the making of a soap also reduces the volatility of the fatty acid, particularly with Mg and Ca, this
also helps.
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I doubt is glycerol has much to do with it. I worked for years in material development, including oodles of sulphur vulcanised rubbers. Well, even
these glycerol-free processes stink, even though the raw materials are of very high MW.
Model studies of very low molecular weight dienes, sulphur vulcanised with accelerators, showed tens of sulphur bearing structures and byproducts to
be the reaction product mix. And these stink to high heaven, as we know.
I also kind of fail to see how sulphur would affect the ester bond.
Factice producers use the oil rather than the fatty acids because a higher viscosity gel is obtained with the oil. Or so I've read...
Perhaps we should see what happens if a methyl fatty acid ester is heated with sulphur?
[Edited on 22-3-2015 by blogfast25]
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aga
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Sounds like i have to get some Linseed oil and do a whole series of experiments.
Reminds me of the CHRIS25 Aluminium Sulphate Saga.
Well, we succeeded on that one, so i guess it can be done.
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deltaH
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| Quote: Originally posted by blogfast25 | | Quote: Originally posted by deltaH |
I strongly advise making soaps from the oils first and ditching the glycerine, I have a strong suspicion that it's the main culprit for making the
severest stinks by way of volatile thiols. Also the making of a soap also reduces the volatility of the fatty acid, particularly with Mg and Ca, this
also helps.
|
I doubt is glycerol has much to do with it. I worked for years in material development, including oodles of sulphur vulcanised rubbers. Well, even
these glycerol-free processes stink, even though the raw materials are of very high MW.
Model studies of very low molecular weight dienes, sulphur vulcanised with accelerators, showed tens of sulphur bearing structures and byproducts to
be the reaction product mix. And these stink to high heaven, as we know.
I also kind of fail to see how sulphur would affect the ester bond.
Factice producers use the oil rather than the fatty acids because a higher viscosity gel is obtained with the oil. Or so I've read...
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At high temperatures triglycerides crack and release small amounts of glycerine which can then react with sulfur to make water and thiols, at least in
theory....
Industrial factice is not necessarily a good rubber, it's blended with normal rubber to give a nice finish to it, that's why the industrial ones can
be made from things like rapeseed oil, that gives gelatinous stuff, but not what we're after.
A free fatty acid if it's linolenic acid has only three doubly bonds to react with sulphur, but magnesium linolenate has six, so that's why the soaps
are harder. The Ebewele paper on page 1 has the proof of the pudding.
[Edited on 22-3-2015 by deltaH]
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deltaH
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| Quote: Originally posted by aga | Sounds like i have to get some Linseed oil and do a whole series of experiments.
Reminds me of the CHRIS25 Aluminium Sulphate Saga.
Well, we succeeded on that one, so i guess it can be done. |
It's really easy actually, there's a step by step photo essay on page three for making the magnesium 'linolate'
All you need is linseed oil, lye and Epsom salts, all OTC.
[Edited on 22-3-2015 by deltaH]
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aga
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Got them all, apart from Linseed Oil.
Acquistion expedition tomorrow.
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blogfast25
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An important point is like other vegetable oils/animal fats, linseed oil is not a pure trigycleride.
From Wiki (composition of linseed oil)
| Quote: | The triply unsaturated α-linolenic acid (51.9-55.2%),
The saturated acids palmitic acid (about 7%) and stearic acid (3.4-4.6%),
The monounsaturated oleic acid (18.5-22.6%),
The doubly unsaturated linoleic acid (14.2-17%). |
So saponifying linseed oil does not strictly yield a 'linolate' but rather a mix of soaps.
And, based on their fatty acid profiles I'm still at a loss why linseed oil does gel with (a lot of) sulphur but sunflower oil does not.
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aga
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Well, we all have to learn.
Best thing is to mess with stuff and see how it behaves.
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blogfast25
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| Quote: Originally posted by deltaH | At high temperatures triglycerides crack and release small amounts of glycerine which can then react with sulfur to make water and thiols, at least in
theory....
Industrial factice is not necessarily a good rubber, it's blended with normal rubber to give a nice finish to it, that's why the industrial ones can
be made from things like rapeseed oil, that gives gelatinous stuff, but not what we're after.
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Industrial factice isn't really rubber at all, it's MW is far too low for that. Good quality rubber has tensile strength of up to 20 MPa, rubber
factices you can slice with a knife like butter. We did use to add factices to rubber compounds, mainly for extruded goods.
Rubber factices are quite low MW, if they weren't you could never incorporate them into green (uncured) rubber compounds. 'Gel factice' would be a
better term than 'rubber factice'.
As the C=O, C-O and H-O bonds are all stronger than their sulphur equivalents, I think trigyceride esters should be quite resistant to attack by
sulphur, except of course for those double bonds.
[Edited on 23-3-2015 by blogfast25]
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blogfast25
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Actually, assuming we're talking about the same paper:
Polymer processing aid from rubber seed oil, a renewable resource: Preparation and characterization. R. O. Ebewele1, A. F.
Iyayi2*, F. K. Hymore3, S. O. Ohikhena4, P. O. Akpaka2 and U. Ukpeoyibo2
...then it does nothing of the sort. The paper isn't concerned with soaps and uses only rubber seed oil (RSO) in its experiments, not soaps of it,
magnesium or other.
It does evaluate MgO at 10 parts per 100 parts of RSO, as an accelerator/modifier in the vulcanisation of RSO.
I'm surprised they don't seem to realise that in sulphur vulcanisation of rubber, zinc oxide (ZnO) is considered the
invaluable and indispensable component. No sulphur vulcanising system goes without 5 to 10 parts of ZnO, per hundred parts of rubber.
So that might be something to consider, to improve crosslinking and obtain a simpler (read: shorter S links) crosslink network.
[Edited on 23-3-2015 by blogfast25]
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deltaH
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| Quote: Originally posted by blogfast25 |
So saponifying linseed oil does not strictly yield a 'linolate' but rather a mix of soaps.
And, based on their fatty acid profiles I'm still at a loss why linseed oil does gel with (a lot of) sulphur but sunflower oil does not.
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'Linolate' is my made up word for soaps of linseed (of all fatty acids), which is why I try to enclose it in quotes. Linolenate, linoleate, palmitate
etc. on the other hand, is specific and real (referring to their respective acids) and so magnesium linolenate is a major component of a magnesium
'linolate'. It's a bit confusing, sorry 
As for why linseed oil works better, I think that there are more 'sites' for vulcanisation with the triple unsaturated fatty acid oils and so more
chance to have continuity in cross links between sulphur chains across the polymer network as a whole and so a more rigid structure.
| Quote: Originally posted by blogfast25 |
Actually, assuming we're talking about the same paper:
Polymer processing aid from rubber seed oil, a renewable resource: Preparation and characterization. R. O. Ebewele1, A. F.
Iyayi2*, F. K. Hymore3, S. O. Ohikhena4, P. O. Akpaka2 and U. Ukpeoyibo2
...then it does nothing of the sort. The paper isn't concerned with soaps and uses only rubber seed oil (RSO) in its experiments, not soaps of it,
magnesium or other.
It does evaluate MgO at 10 parts per 100 parts of RSO, as an accelerator/modifier in the vulcanisation of RSO.
I'm surprised they don't seem to realise that in sulphur vulcanisation of rubber, zinc oxide (ZnO) is considered the
invaluable and indispensable component. No sulphur vulcanising system goes without 5 to 10 parts of ZnO, per hundred parts of rubber.
So that might be something to consider, to improve crosslinking and obtain a simpler (read: shorter S links) crosslink network.
[Edited on 23-3-2015 by blogfast25] |
The devil's in the details blogfast  I've mentioned earlier in
this thread that I noticed in that paper that their rubber seed oil is unusual in that it has a very high content of free fatty acids
(FFA), some 38% in fact (it's in the 'materials and methods' section), so yes, mixing that with MgO and cooking up would make the Mg soap. It's a
simple neutralisation reaction, not saponification, that proceeds easily. I also made the point that our everyday oils are typically quite low in
FFA's by comparison and so replied to fullen's posts that I didn't think he achieved any significant saponification when he simply
heated MgO with rapeseed and linseed oils because those don't contain such large amounts of FFAs and require traditional saponification methods if you
want to convert them fully to Mg soaps.
Look, I might be barking up the wrong tree here with working with the Mg soaps, but I have a hunch they might (a) help to reduce the stench and (b)
make a harder factice. This is hypothetical, of course, which is why I am doing the experiments to see...
The ZnO you speak of, does it have to be freshly precipitated high surface area stuff? I still have lots of ZnO left over from my experiments with
zincates, it's calcined pharma grade. It seemed rather inert and I struggled to dissolve it as is in sodium hydroxide solutions back then. It did,
however, dissolve in acid, so in you experience, do you think that would work as is, because I'd be very happy to use it 
[Edited on 23-3-2015 by deltaH]
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deltaH
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Managed to boil my ferric 'linolate' only for a few minutes before masses of dark and viscous red oil prevented me from continuing. Because of it's
viscosity, it started to balloon instead of releasing the water vapour bubbles nicely. Looked like boiling lava mounds 
It smells and dries very much like wood varnish... I really wish I owned a garage with a garage door that needed painting
Anyhow, I get the feeling this red oil is just ITCHING to harden up, I just need to get the bubbles out and to separate the water entrapped in it. I'm
not keen to dilute it to drop the viscosity, sigh... it's a pain in the ass.
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hyfalcon
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Try vacuum.
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deltaH
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Finally got some sulphur and have two substrates to play with... stinky time
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deltaH
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UPDATE: Okay, mixed 50 pho sulfur (yes I know it's very high, but about what would be necessary for a propellant) with my nice yellow magnesium
linolate paste. Made a butter like material, but still very soft, like an oily paste. I placed a pea-sized bit on a SS spoon and attempted to
gently/gradually heat it over a flame.
This produced an intense sulfur smell and small amounts of white fume, exactly as melting sulfur over a flame smells and looks. I'm pleased to report
that it didn't produce any nasty organosulfur type smells, just strong sulfur fumes. It took me back to my childhood, making black powder.
I struggled to cook the factice in my spoon, the back charred while the top turned dark brown, but soon everything was char
Overall, it looks promising in terms of smell reduction, but a pea-sized experiment won't do. I'm less scared of it now that I've established it
appears like 'just' sulfur fumes coming off. The residue wasn't too smelly either, so I'm really happy about that.
I need to buy some test tubes and repeat with slightly more of the 'special butter' and try to heat it more slowly this time around. I have a high-temperature thermometer, beaker and gauze, so I might use a small oil bath and
target 160°C and immerse the test tube into it with some foil over the top. If the factice gets hard and stuck, I can always smash the test tube to
free the melt.
I'll be heating incrementally and taking some photos.
[Edited on 23-3-2015 by deltaH]
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