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cyanureeves
National Hazard
Posts: 744
Registered: 29-8-2010
Location: Mars
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Mood: No Mood
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looks like the stuff used to patch holes in mufflers.maybe an already hot surface like an exhaust pipe will drive off the xylol quickly to form a
solid.it could be used to make the outer shell of a sound suppressor and if it can hold the shape of female end threads,better yet.i would be safe
down here in the summer time but come winter i will be fair game.watch out for the xycal varmint suppressor.if you walk into the woods and hear
nothing,it already gotcha!
[Edited on 10-10-2015 by cyanureeves]
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deltaH
Dangerous source of unreferenced speculation
Posts: 1663
Registered: 30-9-2013
Location: South Africa
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Mood: Heavily protonated
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You mean like Pratley putty? Yes, it does resemble it very much.
Another possibility is maybe to slake the lime much less (i.e. use no water or very little water and melt in a microwave), that might help form
calcium alkoxides with the polyol when heated hot so that it doesn't melt?
I'd be more interested to keep the polyol in place than drive it off to be honest, since one might form some kind of carbon binder on heating by loss
of water (same as pyrolysing sugar)... some carbonaceous calcium oxide composite thing?
If you could get that to be glassy, WOW WOW WOW.
In terms of that, a very slow heating ramp is apparently important.
https://en.wikipedia.org/wiki/Glassy_carbon
The stuff's valuable as hell!
[Edited on 10-10-2015 by deltaH]
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deltaH
Dangerous source of unreferenced speculation
Posts: 1663
Registered: 30-9-2013
Location: South Africa
Member Is Offline
Mood: Heavily protonated
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I finally got around to messing around a little more with this. Nothing particularly exciting to report.
Xylitol and erythritol eutectic + quicklime in similar proportions as xylitol + quicklime yields a nearly identical material. I have formed a flate
plate of the material and will wait to see if crystal blooms develop over the next couple of weeks.
Eutectic + calcium gluconate lactate (CGL) was a flop, yellowing started on strong heating indicative of condendation reactions. Evidently the CGL is
too basic for this system. Nothing particularly interesting formed on cooling beside a tacky goop typical of sugar with some crystallisation,
presumably the CGL.
I have boric acid, so decided to experiment with borate condensations. 1:1 molar xylitol and boric acid when heated yields much water, presumably
either borate esters are formed or the boric acid dehydrates to metaboric acid or both. On cooling, a crystal clear glass results, which was cool, but
it's brittle and weak, so not as much fun to play with as my putty.
The putty is still the most interesting to me, particularly because of its relative hardness and strength. I wish I understood what was going on.
I feel somewhat confident that the lime slakes, but that slaking in conc. sugar alcohols results in a very different morphology. I can speculate that
perhaps this forms a more amorphous calcium hydroxide-sacharate. When you dissolve the putty in excess water, you suddenly see voluminous amounts of a
bright white material form with the consistency of a thick cream (but initially it's viscous but not gel like), but this happens only after addition
of a certain amount of water, so I definately think there is some interaction between the polyol molecules and the calcium hydroxide in this putty
form, upon excess dilution you get almost a phase change into ordinary slaked lime and dissolved polyol.
Kneading seems important during the cooldown, it improves the slaking and makes the resulting putty very clay-like. I wish I could automate this
kneading, it's very hard to do it at the high temperature even when wearing thick gloves. What I need is REALLY thick rubber gloves to be pain-free
Anyway, that's all for now, what I'm keen to see is if this erythritol eutectic employed will stabilise the material against crystallisation blooms
that set in after several days. Crossing fingers.
I want to try to make some kind of casting with this stuff if I can and play with colouring it, but for that I need it stable long term first!
I also need a kenwood machine for the kneading of larger quantities. A heated bowl would not go amiss to keep this soft, easily done with a steel bowl
Oh forgot to say that the putty is initially slightly tacky like a sugar, but after 48h its not tacky at all and similar to a matt ceramic. Presumably
the surface forms some calcium carbonates that passivates it from being tacky, so if any of you make this and are disappointed with the initial
stickiness, just put your piece aside for 48h, it will correct itself.
[Edited on 26-11-2015 by deltaH]
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