deadrush
Harmless
Posts: 34
Registered: 3-3-2014
Location: Worcester MA
Member Is Offline
Mood: Fungible
|
|
Powdered polystyrene (for copolymerization)
How might one achieve this without a ball mill? I read (I believe Google AI) that it could be accomplished using a solvent somehow. I know that if I
let it evaporate in a thin enough layer that it would basically crumble and I could toss it in a coffee grinder but I doubt that it what it was
referring to. I'd ideally like a fine powder but it need not be better than what a coffee grinder would produce.
Thanks and...
Happy holidays everyone!
[Edited on 25-12-2024 by deadrush]
|
|
|
pesco
Harmless
Posts: 43
Registered: 19-11-2015
Member Is Offline
Mood: No Mood
|
|
As kid I used to make a varnish by dissolving polystyrene in point stripper/thinner in my country called "nitro". It is a mix of different
hydrocarbons with main ingredients being toluene and acetone.
If you paint that varnish onto some flexible surface you could then peel off thin layers and powderise it.
Cling film comes to mind. There are cling films made out of different materials, so if the first one wont work try with different one. A bit more
expensive and less likely, but possible, that aluminium foil will also work.
Do a small test to find out how easily it peels off.
Another substrate would be something what is water soluble. Maybe first paint with sugar water, let the sugar dry up and then paint with polystyrene
varnish. Once it dries you could dissolve sugar with water which could be reused for another batch.
Then just strain the polystyrene fragments, dry it and powderise.
|
|
|
Rainwater
National Hazard
Posts: 991
Registered: 22-12-2021
Member Is Offline
Mood: Break'n glass & kick'n a's
|
|
A screw drive and nozzle. Works for many thermoplastics.
Nozzle diameter will determine the pellet size
"You can't do that" - challenge accepted
|
|
|
bnull
National Hazard
Posts: 634
Registered: 15-1-2024
Location: The country that made an art of fence-sitting
Member Is Offline
Mood: I'm back, sort of.
|
|
It is a process called spray drying. The substance is dissolved in an appropriate solvent (choose one from Common Solvents and Non-Solvents of Polystyrene). The solution is atomized on a current of hot and dry air, leaving behind a fine powder. If I'm
not mistaken, it is the process used to make powdered milk. Edit: I forgot to mention that I don't recommend it. It is not
amateur-friendly, and the chances of you sending your lab and yourself to Kingdom Come are pretty high. It is interesting, of course.
What is your source of polystyrene? If it is a bulky one, you can use a rasp, a sort of file with pointy scales, to shred it to smaller, grindable
pieces.
[Edited on 27-12-2024 by bnull]
|
|
|
pesco
Harmless
Posts: 43
Registered: 19-11-2015
Member Is Offline
Mood: No Mood
|
|
Spray drying works great and I used it few times with water soluble stuff like salts or sugar from beets etc.
Regarding solvent removal I would strongly discourage spray drying in backyard setting. Difficult to capture the solvent vapours what means air
pollution and health risk and most dangerous aspect is the potential for explosion.
When you have amount of hot solvent vapour then tiny spark, a bit of UV coming from the Sun or just some compression/friction might set it off.
|
|
|
Fulmen
International Hazard
Posts: 1752
Registered: 24-9-2005
Member Is Offline
Mood: Bored
|
|
You might get somewhere by crashing it out in water. Dissolve the PS in a solvent that's miscible in water (acetone perhaps), then slowly pour it into
a large amount of water with vigorous stirring.
We're not banging rocks together here. We know how to put a man back together.
|
|
|
RedDwarf
Hazard to Others
Posts: 169
Registered: 16-2-2019
Location: UK (North West)
Member Is Offline
Mood: Variable
|
|
Are you really talking about creating a copolymer or just a polymer blend? As far as I'm aware you'd need to start from the monomers to create a
copolymer (In the case of polystyrene creating styrene monomer is relatively easy and you wouldn't need to create a powder of the polystyrene first).
Copolymers and polymer blends have very different properties so it's not just a question of semantics.
|
|
|
kmno4
International Hazard
Posts: 1517
Registered: 1-6-2005
Location: Silly, stupid country
Member Is Offline
Mood: No Mood
|
|
At last one user, who sees the difference 
Besides, "powdered" form of PS can be obtained by mixing its solutions (in toluene etc) with methanol. But it is important to do this right, to avoid
gel formation. However, such procedure is nothing new.
Слава Україні !
Героям слава !
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
