Author Topic: Pressurized Isobutylene..  (Read 2061 times)

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  • Guest
Pressurized Isobutylene..
« on: May 28, 2003, 09:03:00 PM »
What's up, folks?! I want to know how I could keep isobutylene under pressure in a glass vessel.. I'm talking about one of those 1 gallon pickle jars. If I had an air-tight hose rigged to the jar from a tank of isobutylene and let it into the jar, would it explode, sending shards of glass into my face, making my life more miserable, or could it take the pressure? Should the glass vessel be surrounded by vinyl cement or epoxy, or would this be unnecessary? Isobutylene's boiling point is -6.9*C.. This compared with -0.5*C for butane makes me nervous! Btw, in the vessel, it would be in combination with N,N',N"-trimethylhexahydro-1,3,5-triazine and acetic acid, like in

Patent US2765315

(prodine analog). What do you think? Any suggestions? Peace! 8)


  • Guest
« Reply #1 on: May 28, 2003, 09:07:00 PM »
you'll definetly want something between you and the jar.  I don't think a simple pickle jar will provide the resistance you'll need to carry out a pressurized reaction (as this will be due to the low BP of Isobutylene)


  • Guest
in situ isobutene
« Reply #2 on: May 29, 2003, 11:25:00 PM »
Isn't isobutylene often made "in situ" or in a neighbouring flask by elimination reactions of certain tert-butanol esters?
I think I have read that somewhere, and it doesn't sound completely far out...


  • Guest
In Situ
« Reply #3 on: May 30, 2003, 06:19:00 AM »
Even if the isobutylene is made in situ, the pressure will still build up (maybe more slowly) if the reaction does not take pace quickly enough.  How fast does the reaction proceed?


  • Guest
if it must be a pickle jar...
« Reply #4 on: May 30, 2003, 12:43:00 PM »
Probably everything else but a pickle jar is a better pressurized reaction vessel, but if you are determined to go down this road, then you should think about getting a fiberglass autobody repair kit. Spread the resin on the very clean outside of the picklejar, smooth on the woven fiberglass fabric and cover with the rest of the resin. Your unstable, unreliable "reaction kettle" will be far less likely to do you grievous bodily harm because the fiberglass cloth will contain the shards which would rather fly in your face. In the event of an emergency, you'll still lose the reactants, but you'll keep your eyesight and be able to see them coat the floor, walls and ceiling.
     Or perhaps you could find a kettle, lid and clamp at the online auction site of your choice?


  • Guest
mason jars
« Reply #5 on: May 30, 2003, 07:55:00 PM »
why does it have to be all glass? you could wrap a glass 4L cider jug in strands of fiberglass fabric and epoxy. though you wouldnt have to wrap it solid, just do a netting pattern around the outside. (thick bands of glassed fiber would retain enough strangth) that way you could still watch the reaction go on inside. now, it would be really cool if you could use that for all sorts of high positive pressure reactions if you could rig a high-pressure equalized addition funnel in the same method. perhaps high pressure would be sufficient to perform the p-benzo oxidation over PdCl2 without causing any thermal polymerisation. it might need some heat to get it started...

the pressure could be monitored using a loaded piston. piston position could be calibrated to the different weights of springs that you were using depending on scale/reaction ect... you could also pressure-rate all your components (though im sure you could buy all sorts of pressure guages) it could provide your system with some elasticity, and a valve could be blown automatically at a set pressure.

what if you put your setup at the bottom of a swimming pool? (external cooling, the shock wave would get you if it blew in the pool and you were in it) no, thats a dumb idea. although, all your measurements could be read poolside on long hoses (with safety valves) and if it did go to shit, then hey, break into a different pool next time cuz it would be poisonous as hell! yeah, thats a dumb idea.



  • Guest
Get the tank cold enough, (dry ice/acetone)...
« Reply #6 on: May 30, 2003, 08:45:00 PM »
Get the tank cold enough, (dry ice/acetone) and you should bee able to basically pour out liquid isobutylene.  Add the liquid to a (**PRECOOLED** especially if your using a pickle jar which is probably temperature shock sensitive) reaction vessel that is in a dry ice/acetone bath or even a regular ice/salt water bath will robably work fine.  UTFSE for cold baths.

Or if ithe reaction has to bee run under pressure or at elevated temps you might want to try slow addition if the isobutylene as Rhodium mentioned.(I didn't look at the patent)


  • Guest
it has a low vapor presure
« Reply #7 on: May 31, 2003, 06:15:00 AM »
i don't know what you will be doing with the butain but. ive stored butain in mason jars at room temp and they build up a bit of pressure. but when stored in the frezzer. its a lot less presure.


  • Guest
plastic bottle
« Reply #8 on: May 31, 2003, 07:18:00 AM »
polymers are often deplasticied by around -10oC depending on the type of monomer unit. This can cuase the vessel to because brittle and due to the thickness of the plastic very likely to cause cracks or even shattering under force or pressure. You might want to find out some infomation on the plastic before you use it if you took this route.