omegawolf_1362... - 15-10-2010 at 10:30
i am trying to figure out how to recover styrene from polystyrene,
wiki says "styrene tends to polymerize. To minimize this problem, early styrene plants added elemental sulfur to inhibit the polymerization"
i know heating polystyrene gives styrene,
so i guess what i'm asking is, could you heat polystyrene with molten sulphur and collect a more stable mono-styrene.
hissingnoise - 15-10-2010 at 11:51
Sulphur was added to styrene prior to distillation because polymerisation was a problem at styrene's boiling point . . .
If you keep the stuff cold it should remain liquid!
not_important - 15-10-2010 at 13:04
Actually styrene will polymerise at STP, generally slowly but occasionally rahter rapidly giving "popcorn" polystyrene. Hydroquinone, BHT, and
similar free radical glommers will work to inhibit polymerisation, keeping oxygen/air away helps too. Sulphur works, it's cheaper than the others but
not as effective and harder to remove from the styrene when you want to use it; hydroquinone can just be washed out with water or ignore as very small
quantities are needed.
When cracking (distilling) polystyrene, polymerisation inhibition in the still pot generally isn't needed, but an inhibitor in the receiver is a good
idea. Strong blut-to-UV light helps the heated polymer split apart, some acidic catalysts do the same - there's a patent using MgSO4 for that.
omegawolf_1362... - 21-10-2010 at 02:24
ok, nice one,
i thought because sulphur boils at 444.6 c, i could crack and recover stabilized styrene out of one pot.
removing the sulphur from the styrene isn't a problem,
this is more a proof of concept kind of thing.
will look up that patent 