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Author: Subject: perfluoro sulphonic acid synthesis?
Nitrous2000
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[*] posted on 20-3-2021 at 10:43
perfluoro sulphonic acid synthesis?


Hey Folks,

Anyone have any experience with making/obtaining this compound? I have seen some posts around Nafion, and commenting on cost. But nothing around substitutes....

Has anyone looked at the use of ion-exchange resins as a substitute? There are fluoro sulfonate based resins, but they are 1) very expensive and 2) difficult to obtain.

Any suggestions that don't start with perfluorsulfonic acid would be appreciated :)

Thanks
Doug
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njl
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[*] posted on 20-3-2021 at 16:31


Some perfluorosulphonic acids are used commercially as surfactants, and that's really all I (and I think most people here) can add. It would be a very very bad idea to try to fluorinate something like this at home. What do you mean "use of ion-exchange resins as a substitute"? Substitute in what context?



Reflux condenser?? I barely know her!
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clearly_not_atara
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[*] posted on 20-3-2021 at 16:53


This is basically impossible. I'm sure you knew that, but anyway, let's talk about the direct cupration of fluoroform!

https://pubs.acs.org/doi/10.1021/ja2081026

Reacting the fluoroform cuprate with S2Cl2 should give perfluorodimethyl disulfide. Oxidation with hydrogen peroxide gives triflic acid. This is adapted from the Wikipedia synthesis of triflic acid.

Disadvantages: you need tBuOK or a replacement, not sure if other alkoxides work; you probably need non-alcoholic solvents, none of this Na in EtOH bullshit; you need to make S2Cl2; I don't have any idea what the properties of (CF3)2S2 are; we haven't even talked about how to make fluoroform

So anyway, since I picked fluoroform as a starting point, you're probably wondering, gee, how do I make fluoroform? Well, you have a couple of options and they all suck. You can try to make it from various refrigerants; you can decarboxylate trifluoroacetic acid, if you can buy that; you can react bromoform with various metal fluorides below -15 C; you can react formic acid with sulfur tetrafluoride. Of these the bromoform method is the original and most practical.

In all of that time, you could probably have figured out how to steal some... :D




[Edited on 04-20-1969 by clearly_not_atara]
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Dr.Bob
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[*] posted on 20-3-2021 at 17:29


Are you looking for grams or pounds of it? You can get lower MW ones still, like perfluorobutyl which is the replacement for the perfluorooctyl acid and sullfonic acid. But the longer chain ones are almost completely banned now, and the lower chain ones are on the way out also, as they also linger in the environment. Making them directly is nearly impossible without complex equipment. I have heard of taking the bromoperfluoroalkane and make the Grignard, then reacting it with SO2 to generate the sulfonic acid. But that SM might also be hard to find, but not impossible.
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wg48temp9
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[*] posted on 20-3-2021 at 21:51


Apparently 1,3,3,3-Tetrafluoropropene is available as a freeze spray in the UK and probably in other countries as well. For example Artic Spray from ToolStation, 150ml for £11.50. As it contains a double bond I guess its relatively reactive so it may be convertible to a sulphonic acid without too much difficulty.



I also thought it could be polymerized but I wanted to check that. According to several patents yes it can be polymerized for example:

Emulsion Polymerization

"In certain embodiments, the present invention relates to an emulsion polymerization method to produce poly-1234yf. While not limited thereto, the polymerization may be performed using at least one radical initiator provided in an aqueous emulsion solution.

The radical initiators may include any compound that provides free radical building blocks for 2,3,3,3-tetrafluoropropene polymerization. In one preferred aspect, the radical initiator is a persulfate compound or salt thereof. In certain preferred aspects, the persulfate initiators include, but are not limited to, one or a combination of (NH4)2S2O8, K2S2O8, Na2S2O8, Fe2(S2O8)3, (NH4)2S2O5/Na2S2O5, (NH4)2S2O8/FeSO4, (NH4)2S2O8/Na2S2O5/FeSO4, and the like, as well as combinations thereof.

The polymerization may be conducted in any aqueous emulsion solutions, particularly aqueous emulsion solutions that may be used in conjunction with a free radical polymerization reaction. Such aqueous emulsion solutions, in certain preferred embodiments, include, but are not limited to, one or a combination of degassed deionized water, buffer compounds (such as, but not limited to, Na2HPO4/NaH2PO4) and an emulsifier (such as, but not limited to, C7F15CO2NH4, C4F9SO3K, CH3(CH2)11OSO3Na, C12H25C6H4SO3Na, C9H19C6H4O(C2H40)10H, or the like)."

From:- https://patents.justia.com/patent/20170240666

[Edited on 3/21/2021 by wg48temp9]




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[*] posted on 22-3-2021 at 11:31


You can buy hexafluoropropene by the cylinder full. I think it is a by-product of PTFA production. Even more fluoriny. You can react that with CoF3 to make octafluroropropane.
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[*] posted on 22-3-2021 at 14:02


Quote: Originally posted by Nitrous2000  
Hey Folks,

Anyone have any experience with making/obtaining this compound? I have seen some posts around Nafion, and commenting on cost. But nothing around substitutes....

Has anyone looked at the use of ion-exchange resins as a substitute? There are fluoro sulfonate based resins, but they are 1) very expensive and 2) difficult to obtain.

Any suggestions that don't start with perfluorsulfonic acid would be appreciated :)

Thanks
Doug


I spend my days trying to work out how to destroy and or remove these compounds from the environment and here you are trying to make it!:)
I am curious to know why you want to make it? They are basically ubiquitous in the environment at ppt - ppb concentrations. Go to your nearest Defence site and collect as much surface water as you can down stream of the base. Put that water on high porosity (1000 iodine value) GAC to extract it from the water. Then it is over to you, from here I would be looking at methods to destroy the PFSAs.
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