joeedh
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Registered: 10-7-2017
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Ascorbic Acid & KMnO4 As Photoinitiator
Hi all. I'm new here. I've been playing around with ascorbic acid. When mixed with KMnO4 it functions as a radical polymerization initiator; the
KMnO4 oxidizes the ascorbic acid into threonic and oxalate acids and a free radical. Or something like that; I forgot to bookmark my sources (I'll
try and find and post them later once I've found 'em again).
Anyway. I mixed a bit of water, ascorbic acid, and an equal (by weight) of KMnO4, and mixed it with a bit of polyester resin. I put half the resin
in the sunlight and the other half in the shade (both outside). The resin in the sun gelled after twenty or thirty minutes.
I also mixed water and KMnO4 (leaving the ascorbic acid out) and added it to the polyester, and put half of it in the sun and half in the shade like
before. Both halves gelled.
Anyway, those are the experiments I did today. I stumbled on this yesterday when I mixed ascorbic acid, KMnO4 and titanium dioxide powder (as far as
I know it's not a nanopowder), that had a bit of copper chloride in it. I had this dumb idea about a titanium-copper-KMnO4-ascorbic complex, which I
realized wouldn't work five minutes after mixing the stuff up. I was pretty shocked when it did, so I did some searching on the internet and found
out about using ascorbic acid and an oxidizer as an initiator. Thus today's experiments.
What I don't understand is why this is working as a photoinitiator. Nothing I read (and I really need to remember to bookmark these things)
suggested that ascorbic acid/KMnO4 is a photo-initiator. I did read that copper/iron chloride retards the process, but today's experiments with only
using KMnO4/ascorbic acid seems to rule that out.
Anyway, let me know what you think.
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subskune
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ascorbic acid is easy to oxidize. This involves plenty of radicals.
https://de.wikipedia.org/wiki/Ascorbins%C3%A4ure#/media/File...
All of its oxidation states.
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Quaff
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I have an interest in this area. Instead of K permanganate, I dissolve ascorbic acid in 3% H2O2. After a while, the solution turns dark red. I
notice the patent literature doesn't have much on uses for oxidized vitamin C, I think this is a fertile area, easy to make, but also involves some
know-how, which qualifies any development for good trade-secret protection.
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