| Pages:
1
2 |
Hunterman2244
Hazard to Others
Posts: 105
Registered: 6-6-2018
Member Is Offline
|
|
Useful aromatics from styrofoam
How could one produce aromatic compounds like benzene, phenol, toluene etc from polystyrene? I have scoured the internet, and only seen ways of
production of polystyrene. I was thinking conversion to benzyl cyanide somehow, but that really doesn't help.
|
|
|
unionised
International Hazard
Posts: 5102
Registered: 1-11-2003
Location: UK
Member Is Offline
Mood: No Mood
|
|
It's fairly easy to convert it to styrene
https://www.thevespiary.org/library/Files_Uploaded_by_Users/...
Reaction with potassium permanganate turns styrene to benzoic acid (and CO2).
Styrene is quite reactive so there are lots of options.
|
|
|
wg48
National Hazard
Posts: 821
Registered: 21-11-2015
Member Is Offline
Mood: No Mood
|
|
Quote: Originally posted by Hunterman2244  | | How could one produce aromatic compounds like benzene, phenol, toluene etc from polystyrene? I have scoured the internet, and only seen ways of
production of polystyrene. I was thinking conversion to benzyl cyanide somehow, but that really doesn't help. |
I suggest you search the forum and the net using terms like polystyrene thermal degradation, recycling.
Borosilicate glass:
Good temperature resistance and good thermal shock resistance but finite.
For normal, standard service typically 200-230°C, for short-term (minutes) service max 400°C
Maximum thermal shock resistance is 160°C
|
|
|
Hunterman2244
Hazard to Others
Posts: 105
Registered: 6-6-2018
Member Is Offline
|
|
Thanks!
|
|
|
Hunterman2244
Hazard to Others
Posts: 105
Registered: 6-6-2018
Member Is Offline
|
|
| Quote: Originally posted by wg48 | | Quote: Originally posted by Hunterman2244 | | How could one produce aromatic compounds like benzene, phenol, toluene etc from polystyrene? I have scoured the internet, and only seen ways of
production of polystyrene. I was thinking conversion to benzyl cyanide somehow, but that really doesn't help. |
I suggest you search the forum and the net using terms like polystyrene thermal degradation, recycling.
|
All I could find was converting it to p2p, and I have no interest in making drugs.
|
|
|
JJay
International Hazard
Posts: 3440
Registered: 15-10-2015
Member Is Offline
|
|
| Quote: Originally posted by Hunterman2244 | | Quote: Originally posted by wg48 | | Quote: Originally posted by Hunterman2244 | | How could one produce aromatic compounds like benzene, phenol, toluene etc from polystyrene? I have scoured the internet, and only seen ways of
production of polystyrene. I was thinking conversion to benzyl cyanide somehow, but that really doesn't help. |
I suggest you search the forum and the net using terms like polystyrene thermal degradation, recycling.
|
All I could find was converting it to p2p, and I have no interest in making drugs. |
What?? You can make P2P from styrene?? I actually don't think that's easy to do.
|
|
|
Hunterman2244
Hazard to Others
Posts: 105
Registered: 6-6-2018
Member Is Offline
|
|
| Quote: Originally posted by JJay | | Quote: Originally posted by Hunterman2244 | | Quote: Originally posted by wg48 | | Quote: Originally posted by Hunterman2244 | | How could one produce aromatic compounds like benzene, phenol, toluene etc from polystyrene? I have scoured the internet, and only seen ways of
production of polystyrene. I was thinking conversion to benzyl cyanide somehow, but that really doesn't help. |
I suggest you search the forum and the net using terms like polystyrene thermal degradation, recycling.
|
All I could find was converting it to p2p, and I have no interest in making drugs. |
What?? You can make P2P from styrene?? I actually don't think that's easy to do. |
Doesn't seem too hard: https://www.sciencemadness.org/whisper/viewthread.php?tid=76...
|
|
|
JJay
International Hazard
Posts: 3440
Registered: 15-10-2015
Member Is Offline
|
|
Eh, I'm pretty sure that won't work exactly that way, and while a competent chemist could get something like that to function, the procedure is rather
lengthy. I don't see why anyone would bother.
|
|
|
Hunterman2244
Hazard to Others
Posts: 105
Registered: 6-6-2018
Member Is Offline
|
|
| Quote: Originally posted by JJay | Eh, I'm pretty sure that won't work exactly that way, and while a competent chemist could get something like that to function, the procedure is rather
lengthy. I don't see why anyone would bother.
|
Yeah, that was just what came up.
|
|
|
JJay
International Hazard
Posts: 3440
Registered: 15-10-2015
Member Is Offline
|
|
I would consider styrene itself a useful aromatic. I'm personally interested in it mainly because it is a terminal olefin that is cheap and easy to
obtain, and I would like to explore the chemistry.
|
|
|
Hunterman2244
Hazard to Others
Posts: 105
Registered: 6-6-2018
Member Is Offline
|
|
| Quote: Originally posted by JJay | I would consider styrene itself a useful aromatic. I'm personally interested in it mainly because it is a terminal olefin that is cheap and easy to
obtain, and I would like to explore the chemistry.
|
You could say that. I only meant making things that were in themselves useful, rather than like copolymers etc.
|
|
|
JJay
International Hazard
Posts: 3440
Registered: 15-10-2015
Member Is Offline
|
|
Oh... you can hydrobrominate styrene with hydrogen bromide and react with a strong base to make phenyl ethyl alcohols (one or both depending on
reaction conditions)... aqueous bromine will react with styrene to form a bromohydrin that can be reacted with a strong base to make styrene oxide,
which is pretty easy to isomerize to phenylacetaldehyde. There are some pretty easy routes to cinnamyl compounds from styrene. And of course, it can
be used to make plastics.
Styrene is interesting mainly because it can be used in almost all of these reactions (as well as others):
[Edited on 20-8-2018 by JJay]
|
|
|
wg48
National Hazard
Posts: 821
Registered: 21-11-2015
Member Is Offline
Mood: No Mood
|
|
| Quote: Originally posted by Hunterman2244 | | Quote: Originally posted by wg48 | | Quote: Originally posted by Hunterman2244 | | How could one produce aromatic compounds like benzene, phenol, toluene etc from polystyrene? I have scoured the internet, and only seen ways of
production of polystyrene. I was thinking conversion to benzyl cyanide somehow, but that really doesn't help. |
I suggest you search the forum and the net using terms like polystyrene thermal degradation, recycling.
|
All I could find was converting it to p2p, and I have no interest in making drugs. |
Sorry Hunterman I was thinking of PET when I posted that.
Here are some links from googling "thermal decomposition products of polystyrene":
https://www.ncbi.nlm.nih.gov/pubmed/734408
https://core.ac.uk/download/pdf/82156634.pdf
There are many more, you may find a detailed home chemist procedure in there or in this forum.
[Edited on 20-8-2018 by wg48]
Borosilicate glass:
Good temperature resistance and good thermal shock resistance but finite.
For normal, standard service typically 200-230°C, for short-term (minutes) service max 400°C
Maximum thermal shock resistance is 160°C
|
|
|
Hunterman2244
Hazard to Others
Posts: 105
Registered: 6-6-2018
Member Is Offline
|
|
Thanks, Using PET is an interesting route l, it just seems to have low yields.
|
|
|
wg48
National Hazard
Posts: 821
Registered: 21-11-2015
Member Is Offline
Mood: No Mood
|
|
The best method (good yield and simple) for PET uses ethylene glycol. I think there is a procedure for it in the PET thread.
Borosilicate glass:
Good temperature resistance and good thermal shock resistance but finite.
For normal, standard service typically 200-230°C, for short-term (minutes) service max 400°C
Maximum thermal shock resistance is 160°C
|
|
|
Hunterman2244
Hazard to Others
Posts: 105
Registered: 6-6-2018
Member Is Offline
|
|
| Quote: Originally posted by wg48 |
The best method (good yield and simple) for PET uses ethylene glycol. I think there is a procedure for it in the PET thread. |
Yeah, thanks.
|
|
|
VSEPR_VOID
National Hazard
Posts: 719
Registered: 1-9-2017
Member Is Offline
Mood: Fullerenes
|
|
Does anyone have a procedure for preparing benzoic acid from styrene?
P2P would be easy to prepare from styrene in theory as it would only take a hydrolysis followed by controlled oxidation.
Within cells interlinked
Within cells interlinked
Within cells interlinked
|
|
|
JJay
International Hazard
Posts: 3440
Registered: 15-10-2015
Member Is Offline
|
|
Toluene would require less oxidizer.
| Quote: |
P2P would be easy to prepare from styrene in theory as it would only take a hydrolysis followed by controlled oxidation. |
Bullshit. It doesn't have enough carbons.
|
|
|
Hunterman2244
Hazard to Others
Posts: 105
Registered: 6-6-2018
Member Is Offline
|
|
Any procedure for that then?
|
|
|
GrayGhost-
Hazard to Self
Posts: 61
Registered: 31-10-2017
Location: Argentina
Member Is Offline
Mood: No Mood
|
|
| Quote: Originally posted by VSEPR_VOID | Does anyone have a procedure for preparing benzoic acid from styrene?
P2P would be easy to prepare from styrene in theory as it would only take a hydrolysis followed by controlled oxidation. |
Synthesis of benzaldehydes from toluene and its derivatives. (note that obviously substituded toluenes may bee used too)
...Synthesis of benzaldehyde and its derivatives by oxidation of the corresponding toluenes is an important industrial process in pharmaceutic drug
synthesis.
Oxidation of -CH3 group to -CHO is carried w/MnO2 in presense of sulfuric acid. In case if MnO2 is present in excess, aqueous acid is used and if a
stoichometric quantity of MnO2 is taken, conc. H2SO4 is emloyed.
If the rxn is carried out at temp's below 40 C, aldehydes are formed, however, if its temp's allowed to rise to 60-70 C, the main product is benzoic
acid.
citated by Antoncho in the Hive
[Edited on 21-8-2018 by GrayGhost-]
|
|
|
JJay
International Hazard
Posts: 3440
Registered: 15-10-2015
Member Is Offline
|
|
Since you asked: https://hobbychemistry.wordpress.com/2015/03/29/benzoic-acid...
Toluene from styrene may be possible but doesn't look trivial. Benzaldehyde from styrene... hmm... that might not be a terrible idea. Benzaldehyde
will readily oxidize in air to benzoic acid.
I guess you could gas styrene dissolved in a fluorinated solvent with ozone to produce benzaldehyde, then heat the benzaldehyde in thin layer in an
oven to make benzoic acid. I don't have a procedure for that, but I don't think it would be hard. While styrene would require more oxidizer to produce
benzoic acid that way than toluene would, ozone and air are cheap and green oxidizers. Of course, you have to recycle the fluorinated solvent.
[Edited on 22-8-2018 by JJay]
|
|
|
Melgar
Anti-Spam Agent
Posts: 2004
Registered: 23-2-2010
Location: Connecticut
Member Is Offline
Mood: Estrified
|
|
Unless you enjoy picking at globs of hard, charred plastic that have been fused to the inside of your glassware, I'd avoid attempting styrene
pyrolysis as a way of obtaining styrene. Especially when you can just buy it OTC from boat supply places, or just buy it online:
http://www.carbonfiberglass.com/Resin-Systems/gelcoat-gel-co...
Ozonolysis isn't very practical for amateurs, due to how much solvent and product evaporates when you send those quantities of air through it. If
your goal is to actually make benzoic acid from styrene, that just seems masochistic. Benzoic acid isn't very interesting, and it forms as a
by-product of so many reactions where you're actually trying to make something else, that I'm not sure what you'd be able to learn from trying to
synthesize it on purpose.
If you're going to try to use styrene in a more novel reaction, this reaction seems like an interesting one:
http://www.sciencemadness.org/talk/viewthread.php?tid=6513
[Edited on 8/22/18 by Melgar]
The first step in the process of learning something is admitting that you don't know it already.
I'm givin' the spam shields max power at full warp, but they just dinna have the power! We're gonna have to evacuate to new forum software!
|
|
|
DavidJR
National Hazard
Posts: 908
Registered: 1-1-2018
Location: Scotland
Member Is Offline
Mood: Tired
|
|
| Quote: Originally posted by Melgar | | Unless you enjoy picking at globs of hard, charred plastic that have been fused to the inside of your glassware, I'd avoid attempting [poly]styrene
pyrolysis as a way of obtaining styrene. |
I can't imagine cleanup would be that difficult - there are numerous solvents which readily dissolve polystyrene. Have you actually attempted this?
|
|
|
Melgar
Anti-Spam Agent
Posts: 2004
Registered: 23-2-2010
Location: Connecticut
Member Is Offline
Mood: Estrified
|
|
| Quote: Originally posted by DavidJR | | I can't imagine cleanup would be that difficult - there are numerous solvents which readily dissolve polystyrene. Have you actually attempted this?
|
When its a partially-pyrolyzed semi-charred lump that probably has some cross-linking going on, it doesn't dissolve to anywhere near the same degree
that pure polystyrene does.
The first step in the process of learning something is admitting that you don't know it already.
I'm givin' the spam shields max power at full warp, but they just dinna have the power! We're gonna have to evacuate to new forum software!
|
|
|
DavidJR
National Hazard
Posts: 908
Registered: 1-1-2018
Location: Scotland
Member Is Offline
Mood: Tired
|
|
From the link in the first reply to this thread:
" The still pot is difficult to clean but on soaking with a few mL of toluene the residual polystyrene will come away from the glass. Some black
residue is formed and can be scrubbed out with soap and water. Because the flask is difficult to clean some instructors set aside enough flasks for
this specific experiment. Continuing the thermolysis until the polystyrene is gone and then scrubbing the residual carbon out with soap and water may
achieve cleaning. Because, as a general practice, it is dangerous to continue a distillation to dryness, we do not instruct students to clean their
flasks in this way."
|
|
|
| Pages:
1
2 |
![[*]](images/xpblue/default_icon.gif){kind=icon}
