UC235 - 2011-11-22
Styrene is prepared by thermal cracking of polystyrene plastic. On redistillation of the crude product, styrene was obtained in 67% yield as a colorless liquid. Due to instability of this product, it was converted immediately to styrene dibromide by reaction with Br2, using DCM as a reaction solvent. After removal of the DCM, recrystallization from 600g of hot, 67% aqueous isopropanol afforded an 82.6% yield of styrene dibromide based on styrene, as a white, pearly, crystalline powder, m.p. 69-71C (uncorr.) The intro music clip is from "Stealing Fat" by The Dust Brothers. I believe this falls under fair use.
@cptorangutang2 I may well do that...sulfonic acid bearing resins give very high yields in some reactions that I'll be doing soon. They are very expensive or I'd buy the small amount that I need.
One thing caught my eye here - How can you say it is one mole of polystyrene in your flask when polymers don't have one defined molar mass? Assuming you weighed the plastic beforehand
good job I've been wondering about depolymerization for some time!
@ignilc Sorry, I'm all out. I didn't want to try and store it unstabilized.
Make a video on ion exchange resin synth, I love your videos!
Love your videos, you help inprove my very very small knowledge of organic chemisty. I smiled when you said blowtorch!
I feel like I should be clapping LOL. But instead, I'm posting. Thank you
@ignilc Well, it sort of happens by itself if you don't add a stabilizer or allow it to remain hot for too long. The product though is rather gelatinous, contains lots of unreacted monomer, and not up to snuff with commercially produced polystyrene. I suspect that you could make a fairly respectable product by adding some polyester resin catalyst (usually MEK peroxide in a solvent) as a source of radical initiator. The resulting mix should get quite hot and harden into a cake of polystyrene.
UC – there are a lot of new, pretty cool organic chemistry guys making some good, flashy product here on youTube, with new, shiny apparatus,some of them even offering 1080p resolution. Interesting stuff, (dancing around the schedule I precursor list,but probably just a coincidence)lots of "likes" and subscriptions.
But you are still the best. Nobody can touch your depth with the mechanisms, uses and references.
I still refer to your experiments here quite often. Finally made some TsOH. For me it was a long climb but well worth it. Thank you for your good and interesting work.
Greetings from Peru UC235 !! Styrene brought me here. I'm doing a polymerization in emulsion with vinyl acetate and palm oil. I think your videos are awesome. Please share more videos as soon as you can.
what kind of gas mask do you use
your videos are amazing! How would you go about polymerizing it back to polystyrene? Then you'd have a sort of homemade PS resin...
Very nice video! can you advise me, how can I extract styrene from the mix of benzene 30%, toluene 10%, kerosene 30% ,styrene 10%, other hydrocarbons 20%. without vacuum rectification! The idea is to get benzene +toluene + kerosine after atmospheric distillation as a yeld, but styrene stop this process after +140 C, the residue start to be with some powder, maybe polimerization reaction. If you have time plz help me with Advise. Thank you!
how you wash your equipment after experience?
Cool! I believe Biofuel are useful to Organic Chemistry!
Great teacher your teaching techniques are forward and empathetic to my need for laymens term explanations in science two thumbs up proud to be human !!!!!!!
Interesting, i liked the last bit.
is exothermic polymerization really something to care about unless its the 2nd or 3rd distillation?
do you alter the vacuum pressure for different reactions? if so what do you use to alter the pressure? ty
Very nice, as always!
Is there any way to remove a double bonded carbon and convert it to toluene? I have noticed that industrially styrene can be prepared from methanol and toluene with a catalyst which is then dehydrogenated from ethylbenzene into styrene, but I could not find any data on the reverse.
Ничерта,что говоришь не понимаю,за формулы спасибо Good,were,were good.
Could the styrene monomer be used to glue polystyrene breaks? How would one induce complete polymerization? I have been gluing polystyrene by dissolving the seams with benzene but that has drawbacks such as loss of precise dimension of the glued object.
Just in case you're curious: UC235 subsequently uses the styrene dibromide to make phenylacetylene.
@UC235 bromides are hard to find, can i use chlorine or iodine to make styrene diiodide or chloride, maybe even chlorostyrene
@science Vlog yes you can, but the chlorine is less specific and may give polychlorinated products,and Iodine is less reactive,so will need either light or a small amount of a peroxide (h2o2) to catalyse the reaction.
did you get the Br2 in DCM from a chem supplier or did you make it yourself?
@UC235 Do you have any styrene left over? It would be really cool if you tried it :P... are you sure that MEK peroxide catalyzes polystyrene?
also is there anyway to convert this to benzene ?
Probably same procedure as toluene to benzene conversion would work.
How do you clean the grease from your ground glass joints?
Solvent on a rag.
Linseed oil does not polymerize by its own. It needs the oxygen to peroxidize and crosslink that way. This generates heat, which can light the flammable peroxides.
Wouldn't it be easier to dissolve it all in acetone, throw it in a flask, distill off the acetone, and and then continue with the pyrolysis? It would be a solid layer of polystyrene - Better heat Transfer.
How the hell do you figure that to be easier than cutting up the PS!? He got the styrene, did he not?
how do you synthesize nitrostyrene
how did you make the Br2? NaBr+H2SO4? it would be cool if you made a vid on that synth, as it is really pleasant to watch your vids, and if I may ask:what is that triangularly folded US flag doing there? be careful as its easy to spill something on it
Would chloroform be an appropriate alternative to the dichloromethane used as a solvent?
@Amos Zoeller I imagine so.
@Amos Zoeller yes, absolutely.
I've long since learned this, but thanks, you two.
Practice; get a good textbook that focuses on naming organics - you will be able to identify them, give them a formula, structure and then be able to draw it out as here.
dissolve polystyrene foam with acetone or any solvent and wait for it to evaporate in a flat surface
cut it into little cubes and done!!
or just throw it all in wet
I bet they'll blend.
Chlorine is more reactive than bromine, but bromine is actually more dangerous because it's denser and it's a liquid at room temperature.
wtf did i just watch :|
I bet they will blend...
can we use a soxhlet extractor instead along with a high boiling solvent like DMSO or propylene carbonate??
jhunkubabu for what
@ignilc haha i'm such an idiot apparently fiberglass resins use mek as a hardener. sorry.
hello
Do you know the production of octoate cobalt?
Please help me.
I really like your videos, but 36 minutes is a little heavy. Just saying.
jared garden - 2016-10-25
Now react the styrene monomer with HBr in the presence of a peroxide in an anit-makovnikov type mechanism to get
2-phenylethyl bromide MWAHAHAHAHAHAHA.