that was below self-ignition. This meant that the "self-ignition" of "boiled" linseed (not really boiled but treated with a metal catalyst) is NOT SAFE at ANY temp - (inside at room temp). So a single rag folded up with boiled linseed WILL SELF-IGNITE - no matter what. This means that it is really the metal catalyst causing the self-ignition. Now - that's how much I know so far. I have not finished... Although it does say that linseed oil on its own will seem dry in a few days but the oxidizing reaction will actually continue for YEARS. haha.
The review also discusses the role of metal complexes of cobalt, iron and manganese in catalysing the oxidative drying of linseed oil, summarising some kinetic parameters such as the rate constants of the peroxidation reactions.So it's really the metal catalysts that cause the SELF-combustion at room temperature...
The lead oxide forms lead "soaps" (lead oxide is alkaline) which promotes hardening (polymerisation) of linseed oil by reaction with atmospheric oxygen. Heating shortens its drying time.So OK so the drying causes oxygen to be taken in, thereby "burned" as heat, and this breaks up the hydrogen-carbon "double bonds" of the Linoleic acid - creating hydroxyl bonds. This is what I've learned so far.. but still not done reading.
I took a dish drying towel and just scrubbed the linseed oil on the tarp - so I just removed quite a bit of "extra" oil. So that should help. Now I'll throw this drying towel in the wash - hopefully the yellow pigment will wash out. haha. NOPE still some yellow pigment on the dish towel. Oops...
So back to the science study pdf link....
OK so as oxidizing occurs the hydrogen peroxide peaks along with CO2 emitted, as oxygen is taken in and self-heating occurs. So after a couple hours at 140 degrees F. (60 celsius) then the process slows down as the hydroxyls increase as a new type of double-bond...
The Volatile Oil odor intensity is much worse in "boiled" linseed oil due to the heavy metal catalysts....but also based on the "extraction" method of obtaining the oil from the plants.
Because Linseed Oil has the highest intensity of fatty acids (over twice the amount of palm oil) therefore it has a higher self-heating capacity as it oxidizes and the double bonds are converted from hydrocarbons to hydroxyls via hydroperoxide reactions.
So at room temperature it took 200 hours for the process to stabilize.
So we're talking at least two weeks of "curing" - if the temp is elevated about normal room temperature even. Amazing!!! That's at 8 hours a day - I've got it hanging in my room now - so hopefully it won't self-combust. haha. I did read horror stories of pure raw linseed oil self-combusting from painter's rags. But that is when they leave the rags piled up.
But it turns out that FREQUENCY is much faster for the reaction (photo-induction as sun light) or UV light - rather than amplitude as HEAT. So heat definitely speeds things up for the reaction but even faster is strong sun light.
So
"no induction for photo-aged linseed oil."So the chlorophyll in the oil acts as a Photosensitizer - with the pigment being activated as the "catalyst."
This creates a "singlet oxygen" from the triplet oxygen in chlorophyll.
And this creates the heat - NOT the hydroperoxide creation from the carbon-hydogen alkyl radical reactions.
So the Peroxyl Radicals are much faster than the alkyl radical reaction...
So because Linseed Oil is Polyunsaturated Acid (linoleic acid) then it oxidizes much faster even at room temperature.
But the glycerides act as plasticizers to moderate the hardening process....
Very fascinating!!
So basically we have quantum entanglement as Photo-Ageing induced Self-Combustion!!
So normally it's the enzymes that then cause the autooxidation into hydrogen peroxides (releasing some volatile aromatics in the process - creating a pungent or rancid odor).
But the metal catalyst is a pro-oxidizer - and this is why self-combustion will definitely happen as the heat builds up.
So Photo-ageing is 260 times FASTER than natural ageing.
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