Decomposition of VG to acrolein

[toughdiamond]

Originally Posted by Sun Vaporer

Tough--Unless it is made by Johnson Creek, it is more then likey PG--only JC has the NON-PG option that I am aware of--most of all the rest are PG----Sun

Thanks.....so in all likelyhood I'm acrolein free
I was beginning to suspect that the nice tingly hit I enjoy when the atomiser gets good and hot might be that stuff But it's probably nicotine, like I thought it was.

[kinabaloo]

Originally Posted by toughdiamond

Thanks.....so in all likelyhood I'm acrolein free
I was beginning to suspect that the nice tingly hit I enjoy when the atomiser gets good and hot might be that stuff But it's probably nicotine, like I thought it was.

Acrolein is a more unpleasant taste/smell than nicotine. A 'tiny' amount was found in tests carried out on behalf of Ruyan, although their juice does not contain VG, as far as I know. Likely to be higher in VG-based juices.

To get a good dose of nicotine might indeed require a quite high coil temperature as is does not evaporate easily and has a high boiling point. This needs more investigation.

[kinabaloo]

A bit more on VG and acrolein; and formaldehyde.

"dehydration gives acrolein (acrylaldehyde) by tautomerization, and the oxidation product of that would be acrylic acid. Without dehydration there would be so many hydrogen bonding groups available that the boiling point would probably exceed decomposition temperature."

Not sure the point in italic. but looks interesting. Can avoid decomp. some by maintaining water presence perhaps (but this cannot be near 100% in heat of atty coil); but having some small % of water in the mix might be helpful?

VG + heat > acrolein + 2 water

acrolein + oxygen > acrylic acid

So what we see deposit-wise with VG will likely be via acrylic acid?

"The primary use of acrylic acid is in the production of acrylic esters and resins, which are used primarily in coatings and adhesives. It is also used in oil treatment chemicals, detergent intermediates, water treatment chemicals, and water absorbent polyacrylic acid polymers. Acrylic acid is used widely for polymerization, including production of polyacrylates. It is a monomer for polyacrylic and polymethacrylic acids and other acrylic polymers. It is used in the manufacture of plastics, as a tackifier, as a flocculant, in the production of water-soluble resins and salts, as a comonomer in acrylic emulsion and solution polymers and in molding powder for signs, construction units, decorative emblems and insignias. It is used in polymer solutions for coatings applications, in paint formulations, in leather finishings, in paper coatings, in polishes and adhesives and in general finishes and binders."

"Acrylic acid undergoes the typical reactions of a carboxylic acid and, when reacted with an alcohol, it will form the corresponding ester. The esters and salts of acrylic acid are collectively known as acrylates (or propenoates). ...
Acrylic acid and its esters readily combine with themselves or other monomers (e.g amides, acrylonitrile, vinyl, styrene, and butadiene) by reacting at their double bond, forming homopolymers or copolymers which are used in the manufacture of various plastics, coatings, adhesives, elastomers, as well as floor polishes and paints. ... Acrylic acid is severely irritating and corrosive to the skin. Eye contact can result in severe corneal burns and may result in irreversible injury. Inhalation of vapors may cause irritation to the respiratory tract."

Polymers of both acrolein and acrylic acid (and its esters) would be degraded on the heater coil. As increasingly ashed, small light parts may flake off into the air-stream; this may be what SurbitonPete has reported finding. These could potentially be so small as to be invisible to the eye.

Polymerisation - in random lengths - plus degradation might partly account for the wide spread of compounds seen in analysis of the vapor.

Next, potential for formaldehyde:
"On the glycerol molecule, you cannot completely oxidize all 3 -OH groups (to carboxyl), simply because the middle -OH group is attached to a carbon which itself is again attached to two carbons, and can only form a double bond at most with the oxygen (as in acetone).

The most oxidized product of glycerol would be something like dicarboxy-formaldehyde, but I can't find anything about it, and I wouldn't be surprised if it is not stable and will instead form
formaldehyde and 2 CO2.
My first guess here is that glycerol doesn't want to oxidize any further without falling apart."

Sources:
Glycerol-Ethanol fuel gel - Science Forums, The Original
http://www.npi.gov.au/database/subst...rofiles/6.html
http://en.wikipedia.org/wiki/Acrylic_acid

[baddago]

Hey guys, been monitoring this thread, but isn't ECOPure supposed to be a VG mix? Just wondering because it was said on the last page that Johnson's Creek was the only VG based possibility.

[liquidx]

Originally Posted by baddago

Hey guys, been monitoring this thread, but isn't ECOPure supposed to be a VG mix? Just wondering because it was said on the last page that Johnson's Creek was the only VG based possibility.

Intellisig's ECOPure IS VG based.

[skydragon]

I know this is an older thread but I just finished reading it and was wondering if anyone had come up with a conclusion.

[Kurt]

At the risk of coming into this thread at the end, without reading many of the pages between Kin's OP and the last, I wanted to share my thoughts/experience here. I use VG-only juices as much as possible, as PG makes me congested and headachy. At 3.7 V with my 510 batts or PT with inline batt, there is little detection I can tell of acrolein. Even a small amount will BURN and make you tear up. Almost like vaping acid fumes. In my Greensmoke PT though, which is running at 5 V, no inline batt to limit the voltage, the carts are PG-only. If I add even a drop of VG juice to the GS cart, the effect is HUGE...burning, acrid, with the hands unconsciously unscrewing the cart and throwing it out! Ruined completely in one drag. I believe it is because acrolein was formed under the higher temp that requires 5 V or more to be produced.

this is anecdotal, but certainly the GS atty is producing SOME lacrimator (tear-producing, like pepper spray) only when VG juice is introduced. Done the experiment several times, and it is always the same. If I want to be able to add juice to my GS carts when using the GS PT, the juice likely needs to be PG or PG/PGA only, no VG...or else not pure VG, since PG/VG mixtures will boil at lower temps. This does NOT occur with GS batts, which are about 3.7 V, I think (E9 batts). And again, zero problems with the 510 system, which I use 90% of the time.

Anyone else with a high-V PV found this?

[quovadis]

I have many 801 atomizers.
after a few days i leave them unused they get this rotten taste to them.
I assume that this is what the post is covering?
I simply wash out in everclear...and rotten liquid taste goes away.