SM2
Hazard to Others
Posts: 359
Registered: 8-5-2012
Location: the Irish Springs
Member Is Offline
Mood: Affect
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Vinyl Chloride, Not to be trifled in
My beautiful (French) mother died an early age when I was 2.* years old. Ouch. Conger up Pink Floyd Wall material. That is only half the story.
Any rational adult wanting to get better and not live with irrational pain can get help and get in touch with these skeletons in the closet. It is
not easy work, especially for us males, but you have to really want it, and believe me, the alternative is worse. Still, The Wall stands as a
remarkable classic work of artistry. NOW
NOT TO GET TOO OFF TANGENT AND HAVE MY TOPIC MOVED I WILL RESPECT THE SPIRIT OF THESE BOARDS AS BEST I CAN.
The chemical connection, to above, is that vinyl chloride was used in hair spray at the time my mother was alive, and she was using it. We have since
gone back, exhumed, and found that although she did have the BRAC2 (correct me) deformity, there was strong circumstantial and post mortum (tooth DNA)
analysis showing a probable link with vinyl chloride as a mutagenic agent (by the way the DNA had been mutated at certain segments)
NOW, this all news to me, I had begun to wonder for a while weather PVC turnings, perhaps with some epsom salts or other carrier promoter, might be
destructively distilled to yield the monomer. Is this a sane and facile way of thinking about a simple recycling destructive depolymerization?
I am loathe to try unless under the very safest of environments. And, something tells me, the polymer in this case might also yield a diene. We can
expect reasonable disassociations from lower order styrenes and acrylates after clean up, etc.
What about PVC. Pandoras' Box? The word Vinyl scares me to death. Especially being an amateur.
As always, thanks for the time, and great respect to all our hard working mods out there. Thank you!
"Old men who speak of victory
shed light upon their stolen life
they - drive by night- and act as if they're
moved by unheard music." B. Currie
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unionised
International Hazard
Posts: 5126
Registered: 1-11-2003
Location: UK
Member Is Offline
Mood: No Mood
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Heating PVC generally gives a passable yield of HCl and a mixture of things like benzene, but very little vinyl chloride.
IIRC Vinyl chloride is known to be a carcinogen because it produced a cluster of people with an otherwise very rare cancer,
http://en.wikipedia.org/wiki/Angiosarcoma
rather than because it caused a lot of cancers.
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Triazine
Harmless
Posts: 6
Registered: 11-8-2012
Member Is Offline
Mood: No Mood
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As unionised said, you get lots of HCl, some other volatile hydrocarbons, and no vinyl chloride. You also have to heat the crap out of the PVC
(>300 C) under an inert atmosphere (not very amateur friendly). If you're really interested I've attached an (overly)detailed pdf on the subject.
The problem is the bond dissociation energies. The C-Cl bonds are the weakest (~73 kcal/mol), so you generate a lot of Cl radicals. These radicals
then abstract protons from the polymer backbone, giving you HCl and unsaturated byproducts. Teflon on the other hand has no protons to abstract and
the C-F bond is much stronger (~123 kcal/mol). Therefore heating teflon at ~600 C does give you lots of monomer (79%). Only problem is that it is
super toxic (much worse than vinyl chloride) and produces a host of other nasty buggers (like HF and carbonyl fluoride). That's why you should never
burn non-stick cookware.
Attachment: PVC recycling.pdf (690kB)
This file has been downloaded 905 times
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