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The actual chemical reaction occurring during vaporization of THC

Discussion in 'Vaporization Discussion' started by drfe3, May 8, 2014.

  1. drfe3

    drfe3 New Member

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    I was wondering if anyone knew of the specifics of what happens when the THC is turned from liquid to vapor. I've seen (without citation) that the carboxyl group leaves as THC is turned to a vapor, but what does it leave as? a carboxyl group cannot simply leave it must be decomposed to some sort, or reacted with something else.

    Just wondering because for all we know the COOH group could be slightly combusting to CO
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  2. rayski

    rayski Well-Known Member

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    I believe decarboxylation is what you are talking about. Wikapedia says:
    Decarboxylation is a chemical reaction that removes a carboxyl group and releases carbon dioxide(CO2).
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  3. nicelytoasted

    nicelytoasted Vaked Chemist

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    And probably some water as well. The COOH acid functional group is the weakest bonded part of the molecule, and is at the end for easier access. This is why it doesn't require much heat energy to disassociate into its breakdown components, as well as activating the cannabinoid acids into the cannabinoids that we seek, imo.
  4. tuk

    tuk Well-Known Member

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    What happens(or doesn't) if you create(from fully cured plant matter) cannabis vapour using something other than heat?
  5. vap999

    vap999 Well-Known Member

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    Yes, an important part of "the specifics of what happens when the THC is turned from liquid to vapor" is decarboxylation. But decarboxylation results from any heating in its effective range, e.g., >200˚F.

    What is way more relevant to the actual process of vaporization is the combined thermal desorption and vaporization of the heated essential oils, terpenes, etc. We all know these oils/terpenes are very sticky, gunky. Thermal desorption refers to the heat energy dissociating/tearing-off/liquifying the oils/terpenes from their adsorption to (sticking to, sucked-up into) plant structural material (cellulose). Once oils/terpenes are unbound free-flowing liquids, then they can vaporize. Both things are happening at the same time, but you can't vaporize/evaporate without unbinding first.

    This is one reason why discussions of such things as essential oil, terpenes, etc. boiling/vaporization points are largely irrelevant. Lab.-derived boiling point for high purity oils/terpenes (that don't exist as such in nature) simply do not reflect vaporizing the complex mixtures of the natural product.
  6. tuk

    tuk Well-Known Member

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    I'm not convinced heat is essential to creating the important psycho-actives otherwise eating cured plant matter would have little or no effect ....hence my earlier question!

    I've always seen heat as the tool used to turn a solid into gas ...not converting the essential properties per se.
  7. rayski

    rayski Well-Known Member

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    I think you first need to change THCA to THC and CBDA to CBD (decarboxylation).
    After that, vaporization is one way to ingest these actives.
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  8. grokit

    grokit power cosmic

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    The actives have to boil to turn to vapor, so I think heat is required :2c:
  9. RUDE BOY

    RUDE BOY Space is the Place

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    In my little forty plus years enjoying MJ it's been my experience that eating buds that are only cured won't do anything but waste herb, it's still just 'raw' herb.
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  10. nicelytoasted

    nicelytoasted Vaked Chemist

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    Yes, some heat is required to activate the cannabinoid acids into the cannabinoids that we seek, but since the acid functional group is bonded to the molecule so weakly, I believe that even a good cure will possibly activate a small portion of it as it dries.

    The general act of thermal desorption itself (what we call vapourizing), is adding heat to melt the outer covering of the trichomes, to release the cannabinoids, terpenoids, flavinoids, and various other volatile compounds, that are contained within. These are then drawn into the air stream, as a mix of three main phases: volatile gases, semi-volatile aerosols, and non-volatile particulates (what we call vapour), imo.

    I agree with vap999, I just use the boiling points as a general guideline, in this complex matrix, they are just not accurate or precise enough to be relevant, overall, imo.

    edit: I should add that I believe that temperature precision can be just as important, perhaps moreso than accuracy when vaping. If you can keep the temp relatively constant under load, this might be used as a benchmark, especially for medical users. This is where heat retention and good temp control can help along these lines.
    Last edited: May 14, 2014
  11. Quetzalcoatl

    Quetzalcoatl SPACE GOD

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    Yes, curing will cause decarboxylation to an extent, but heat is the easiest way to do it on a massive scale. That's why you can eat enough raw weed and get stoned ;) Have you taken a look at the Herbalizer? It's got a magnificent temperature control.
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  12. tuk

    tuk Well-Known Member

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    I have to say that is not my experience over a similar time scale, I don't eat a lot of plant matter, but I've had plenty success stirring bud into Yogurt without any heat treatments, sure you have to use a slightly higher dose than a heat-based-lung-absorbed delivery system ..but I always put the difference down to the herb passing through the digestive tract before entering the bloodstream whereas the heat-based-lung-absorbed delivery system is a more direct and less filtered pathway to the bloodstream.

    I'm not sure how you would test these things scientifically, maybe injecting heat-treated/just-cured weed directly into the bloodstream and comparing effects would be a way to go ...it hard for me to believe in this scenario the cured herb 'will do nothing'.

    Are there any proper studies to support the decarboxylation/heat pre-requisite?

    I think these are exciting times for cannabis users, with the laws changing around the world it will allow for greater scientific scrutiny, exploration and further development of delivery systems ..in the beginning we had combustion, then vaporization came along & lowered the temperature, the next logical advance is reduce the heat even further or to remove it altogether, I don't know how this will be implented exactly given what we currently think we understand, but in order for the next advance to happen, firstly we have to imagine it....the facts will come later!
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  13. Hippie Dickie

    Hippie Dickie The Herbal Cube Manufacturer

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    Yes. Gray Wolf (icmag.com) knows his stuff and posts a lot of concentrates info on his website:

    http://skunkpharmresearch.com/decarboxylation/
  14. Egzoset

    Egzoset 1SipAToke Vaporist (v3.0)

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    Salutations,

    Water is liquid at room temperature and doesn't even require heat to become vapor, as i often observed in my own nebulizer experiments by the way:


    The nebulization process doesn't depend on heat for its action, ultra-sonic vibrations are at work instead.

    So, what about a THC nebulizer?...

    :peace:
  15. Hippie Dickie

    Hippie Dickie The Herbal Cube Manufacturer

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    i think the fact that the THC goo is enclosed in a waxy shell and is way more viscous than water would make nebulizing harder to accomplish with out a generous application of heat.

    and the ultra-sonic vibrations wouldn't decarboxylate the thc as well as the application of heat - so less bioactives delivered from the herb.
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  16. Egzoset

    Egzoset 1SipAToke Vaporist (v3.0)

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    Salutations Hippie Dickie,

    This makes me think a Mist Maker built to nebulize water isn't likely to work on cannabic goodies.

    :peace:
  17. kittyboy

    kittyboy Well-Known Member

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    I have had my herb tested before and after vaping as I use vape remains for budder.
    I found that vape remains had about 1/2 the amount of the original THC and the CBD rose by about 10%. This was done by an official lab that test so if herb was 15% thc the vape remains was about 7% and if CBD was 4% it might rise to 5 or 6%. The way i had test done was using a bud and then vape remains from same strain. I use MLB and Aromed vaporizers and would never taste popcorn flavor but hit 10-20 draws from a load.

    I surmise that vaping is a easy decarb step in the process. Vape remains make great medibles.

    mod note: Discussion moved from MFLB thread.
    Last edited by a moderator: Jul 17, 2014
  18. pakalolo

    pakalolo RoboMod v3.17 (ticking) Staff Member

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    That's interesting information. How dark was the ABV? Do you prefer low or high temperatures?
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  19. pakalolo

    pakalolo RoboMod v3.17 (ticking) Staff Member

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    I don't want to derail this thread, but this isn't necessarily true. It depends on the particular compound (THC, CBN) and how long the cannabis is heated. Just reaching (or exceeding) a compound's boiling point does not immediately release all of it. Full release takes time, that's why ABV retains some of the active components. Most of us will stop vaporizing when the taste degrades, and that's usually not long enough to get everything. For example, every study I've read that examines the component percentages remaining after vapourizing has found some—including THCA, which is converted into THC at temperatures lower than we use for vapourizing. Full decarboxylation takes up to an hour at 115°C (240°F).

    If anyone wants to discuss this then we need start another thread or find an existing one.

    mod note: Deliberate double post. This post was merged from the Herbalizer thread.
    Last edited: Jul 17, 2014
  20. OF

    OF Well-Known Member

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    Excellent point. How much is left is a function of how much you didn't extract......

    Many of us have run Empirical Tests (like putting the ABV in a HA or Volcano, making ABV extracts or cooking with it) that shows sometimes very little but nasty taste is left.

    Solvent extractions (like QWISO or Butane) will strip out what's left, 'you can't fool the extract'?

    Evaporating THC is much like drying laundry. Enough heat and time will get nearly 100% of it out. I think most Vapists understand this idea when they decide when to reload the unit?

    Interesting stuff, indeed.

    OF
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  21. pakalolo

    pakalolo RoboMod v3.17 (ticking) Staff Member

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    This isn't something that is measured often, but almost every time I've seen test results they've found a surprising amount of THC and THCA (which you'd assume would have been decarboxlylated). It's consistently in the same ballpark as @kittyboy reports, i.e. near 50%.

    This same derail is now happening in two threads. I think I might have to move some posts.
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  22. kittyboy

    kittyboy Well-Known Member

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    I would say that I am not burning the herb with MFLB or Aromed as the heat controls don't allow too much over heating as some vaporizers do. It is a med brown color. On aromed I use temp from 370-410 depending on strain wetness etc. I am always taking 10-20 draws each bowl. I use butter or coconut oil as my way to extract the ABV with a simmer in water for 2 hours and strain system. Makes great results. Don't throw away any ABV IMO
  23. OF

    OF Well-Known Member

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    I'll be the first to admit it's been a lot of years since I studied this good stuff, but I don't see what you mean.

    Does our favorite hydrocarbon (Ethanol) decompose in the still? 3 times to make the 'triple rectified' good stuff?

    Or does old dinosaurs and yard waste decompose in the refinery on the way to my gas tank?

    IMO there's no chemical reaction at all going on in the vaporization and condensation process. You do get it that what we loosely call 'vapor' is really a liquid aerosol by the time it gets to us?

    So the THC evaporates when gets hot enough, at a rate determined by partial pressure and temperature and as it cools down it condenses into 'fog' of sorts. But, like water, it's chemically the same at every step. Or so I think?

    OF
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  24. Enchantre

    Enchantre A short, pithy statement

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    Just as anecdotal evidence, yesterday my hubby had a half-glass of a canna smoothy - some fresh leaves (not cured), a can of coconut milk, and some frozen mango chunks, blended until smooth.

    He felt some effects. Much like a coffee-like buzz. Lasted a few hours. I can only assume that the liver, in its conversion of food to fuel, did convert some over to actives. Of course, he is a total light-weight with cannabis... has no tolerance yet.
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  25. grokit

    grokit power cosmic

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    @OF, there's so many different medically active cannabinoids, you don't think that the ratio of these cannabinoids could change when heat is applied? If so, would this be a chemical change? Or is the strain the only factor in determining these ratios, making them fixed (as long as grow conditions are optimal)?
    :hmm::huh::smug:

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