Keras
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Recovery of styrene monomer from polystyrene
Folks,
I have (or rather: used to have) a one litre bottle of styrene, that I left in store somewhere. When I turned back to it, all the styrene had
polymerised, so it’s now a bottle full of white polystyrene.
If I wanted to recover the monomer from its present form, what should I do? I read here that heating polystyrene at 400 °C over a MgO bed can led to around 70% styrene recovery. By chance, any other method you'd know that'd
require less heat, maybe ?
Thanks.
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njl
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The gist of polystyrene to styrene monomer is mostly thermal cracking as far as I know. There are some catalysts like metal oxides (MgO) that can
either increase recovery or lower the reaction temperature, but you will still have to use high heat. UC235 has a video on polystyrene cracking on
youtube.
Reflux condenser?? I barely know her!
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draculic acid69
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I'm just guessing but 70% seems rather on the low side. Doesn't the uc235 video
Show a much higher yeild using no catalyst?
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zed
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Yields via pyrolysis are pretty good.
For some unknown reason, this video isn't starting at the beginning.
https://www.youtube.com/watch?v=6tEs7P6UUVQ
[Edited on 28-4-2021 by zed]
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unionised
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It used to be a classic school demo.
Just heating the stuff will give you styrene.
But, unless you have some hydroquinone or something to use as a polymerisation inhibitor, it will revert to a polymer again.
Also works with PMMA
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Keras
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Quote: Originally posted by unionised  | It used to be a classic school demo.
Just heating the stuff will give you styrene.
But, unless you have some hydroquinone or something to use as a polymerisation inhibitor, it will revert to a polymer again.
Also works with PMMA
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Oh, I have 125 g of hydroquinone I didn't know what to do with. Thanks a bunch of suggesting this!
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unionised
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I think that's roughly enough for (literally) a ton of styrene.
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njl
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Yielding methyl methacrylate?
Reflux condenser?? I barely know her!
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zed
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Yup! I think I might have posted a procedure...once upon a time.
[Edited on 29-4-2021 by zed]
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njl
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Off topic to this thread, but what did you end up doing with it?
Reflux condenser?? I barely know her!
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Keras
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Had I known (or guessed, rather) that before, I would've added a few mg of it directly to my styrene bottle in the first place.
Talk about late epiphanies… :p
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Swinfi2
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I've done this without any catalyst, bloody stinks and it broke my RBF on cooling. Didn't have any inhibitors to keep the product but it worked well
enough with minimal thought put into it.
That said if the flask didn't break I probably would never have got it clean from all the charing.
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Keras
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Any idea why it broke?
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