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Author: Subject: Solvent storage in freezer?
Chem Rage
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[*] posted on 3-5-2016 at 06:11
Solvent storage in freezer?


Now that the temperatures are on the increase, I am concerned that the rate of evaporation of my organic solvents will increase resulting in losses over time. All of my solvents, apart from my DCM, are currently kept in a dark place, out of any sunlight, in metal cans with screw top lids and disc-shaped metal seals; the temperature where the solvents are stored rarely goes above 15 degrees Celsius.

My DCM is stored in its original plastic (HDPE?) container. Having marked the solvent level on the outside when I first acquired the DCM about 5 months ago, I have found that the solvent level has gone down by about 1cm, indicating loss either by evaporation or slow permeation through the walls of the plastic container. Strangely, though, I cannot smell any DCM whatsoever- not even a trace. The plastic container appears slightly "bloated" but has not softened in any way over the months. I suspect that this bloating is due to DCM in the vapour phase exerting pressure on the container walls (DCM has a high vapour pressure).

Would I be advised to transfer the DCM to a metal solvent can with screw-top lid and disc-shaped metal seals, and store this in my lab freezer? I have plenty of gas-tight PTFE tape that could be applied to the lid of the metal can, if need be.

MSDS data sheets of various organic solvents, including DCM, advise not to store in (I quote) "freezing conditions". Is there any particular reason for this? I mean, the temperature in my freezer can be described as "freezing conditions" in respect of the freezing point of water, but the freezing point of my organic solvents- including my DCM- is well below what can be accomplished with my lab freezer, which is actually a domestic freezer.





[Edited on 3-5-2016 by Chem Rage]
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XeonTheMGPony
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[*] posted on 3-5-2016 at 07:40


I store all my solvents in the fridge and freezer.

I do painting/epoxy/plumbing stuff allot, by keeping those materials in the fridge has kept them potent for years (I seriously mean it, I had a can of pvc glue in the fridge for 2 years and still got it and use it!)

I all so keep my acids in the fridge as well, but have a dedicated fridge for them. (All my chemicals)

Most the fuming acids I keep in the freezer, Organic solvents and ketones/peroxides I keep in the fridge. Handy too for synths that you need cold acids for ;)

Kicks on at 5.0c and off at 0.5c.

[Edited on 3-5-2016 by XeonTheMGPony]
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[*] posted on 3-5-2016 at 13:33


I have been working to figure out DCM storage as well. I have it in a 125 mL glass bottle with a plastic cap. It resides in a mini fridge dedicated to chemicals at around -10 C and I'm losing around 10% monthly. I don't see the problem with keeping it at lower temps.

DCM eats a lot of plastics. It's listed as methylene chloride on both charts below. Those show that it's incompatible with HDPE and LDPE. I read somewhere a suggestion that it be stored in a glass reagent bottle with a ground glass stopper and a small amount of silicone grease on the stopper. I haven't had a chance to try it yet.

http://www.usplastic.com/catalog/files/charts/LG%20CC.pdf

http://www.coleparmer.com/Chemical-Resistance
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a nitrogen rich explosive
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[*] posted on 3-5-2016 at 13:54


I keep all my stuff in many different places... I have a small fridge just full of tetrazoles!

Yes. Transfer DCM to a metal container.




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Chem Rage
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[*] posted on 5-5-2016 at 03:10


Quote: Originally posted by a nitrogen rich explosive  
I keep all my stuff in many different places... I have a small fridge just full of tetrazoles!

Yes. Transfer DCM to a metal container.


Storing energetic materials- let alone synthesising them- is just asking for trouble! Not just from a safety standpoint, but also a legal one, too.

I personally have always steered clear of energetic materials chemistry, as interesting as it is as a subject, because of these very reasons.

Not that long ago I had a police visit for what they referred to as "suspicious" chemical purchases. A while back I purchased some hexamine and weak (11%) hydrogen peroxide months apart from each other; each for their own separate and independent intended applications:

Hexamine is an interesting heterocyclic compound that has its uses in organic (e.g. Duff reaction) and inorganic (e.g. interesting metal coordination complexes) chemistry alike. Also, I never know when I might go fishing/camping next, being an avid outdoors/bushcraft fan. Hexamine makes an excellent smokeless fuel with a high heat output. For these reasons, and also considering that it is becoming increasingly difficult to acquire (at least for the amateur chemist and general public), I decided to buy some.

As for the 11% hydrogen peroxide- where do I start? It is incredibly useful and versatile. I can't think of a single chemistry lab that does not have hydrogen peroxide in some concentration; it is a fundamental "work horse" chemical. 11% H2O2 is not even strong enough to cook up energetic materials favoured by those who wish to inflict harm.

I explained to them that no, I did not purchase said chemicals with the intent of making what they were possibly thinking, and that I am an amateur chemistry enthusiast with a BSc (Hons) in chemistry. I further explained that both hexamine and 11% hydrogen peroxide have legitimate uses both in chemistry and as consumer products, and that both are perfectly legal to purchase. Satisfied that I was not up to ill-intent, they went on their way. They were polite and level-headed chaps.

[Edited on 5-5-2016 by Chem Rage]
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a nitrogen rich explosive
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[*] posted on 5-5-2016 at 04:45


I have suitable government permits for energetic materials. All my energetics are kept about 300 yards from my laboratory area, accessible by bicycle.

You are in England, right?

I had 2 policemen turn up once, because of my order of large quantities of 'life-enhancing' aminoguanidine hydrochloride pills and 32% nitric acid. I explained that I do chemistry for a hobby, showed them my permits, and they went away. They were very nice guys.




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[*] posted on 5-5-2016 at 05:15


Quote: Originally posted by a nitrogen rich explosive  
I have suitable government permits for energetic materials. All my energetics are kept about 300 yards from my laboratory area, accessible by bicycle.

You are in England, right?

I had 2 policemen turn up once, because of my order of large quantities of 'life-enhancing' aminoguanidine hydrochloride pills and 32% nitric acid. I explained that I do chemistry for a hobby, showed them my permits, and they went away. They were very nice guys.


I don't know what it is like in the USA where you are based (like the majority of amateur chemists, it seems), but here in the UK a government permit allowing for energetic materials research would only be granted to academics, professionals and organisations (e.g. special effects companies)- not to those amateur chemistry hobbyists who wish to experiment with energetic materials field of chemistry (which is an area of chemistry they really shouldn't delve into anyway, as it is far too dangerous and not worth the academic interest or scientific curiosity- best stick to aqueous or "wet" organic, natural product and inorganic chemistry).

Surely, though, I would assume that an ATF permit for energetic materials research would enable one to buy quality assured and purity-assayed reagents from chemical companies, without having to resort to buying ludicrous quantities of "life enhancement" pills?
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[*] posted on 5-5-2016 at 05:57


Quote: Originally posted by Chem Rage  
Quote: Originally posted by a nitrogen rich explosive  
I have suitable government permits for energetic materials. All my energetics are kept about 300 yards from my laboratory area, accessible by bicycle.

You are in England, right?

I had 2 policemen turn up once, because of my order of large quantities of 'life-enhancing' aminoguanidine hydrochloride pills and 32% nitric acid. I explained that I do chemistry for a hobby, showed them my permits, and they went away. They were very nice guys.


I don't know what it is like in the USA where you are based (like the majority of amateur chemists, it seems), but here in the UK a government permit allowing for energetic materials research would only be granted to academics, professionals and organisations (e.g. special effects companies)- not to those amateur chemistry hobbyists who wish to experiment with energetic materials field of chemistry (which is an area of chemistry they really shouldn't delve into anyway, as it is far too dangerous and not worth the academic interest or scientific curiosity- best stick to aqueous or "wet" organic, natural product and inorganic chemistry).

Surely, though, I would assume that an ATF permit for energetic materials research would enable one to buy quality assured and purity-assayed reagents from chemical companies, without having to resort to buying ludicrous quantities of "life enhancement" pills?


Nothing vested nothing gained. In other words to those who take risks are they who shall earn the reward.

Not every one is content to hide under the proverbial bed. Every one has a right to knowledge and the law has no say in it imo, their is all ways a way around moronic legislation.

You can often get just as good reagents over the shelf, just a few thousand times cheaper! Or in case of a particular project larger volumes with out pesky annoyances from guberment officials and such (Brings me back to moronic legislation, or safety theater more accurately, it does nothing other then to make the sheeple to feel safe)

Here in Canada the health food stores sell 35% peroxides by the liters, Erythritol by the Kg, paint shops sells huge jugs of toluene for 24 dollars a pop (Very pure too) the big box stores hexamine (Wax binder simple to remove)

Thank fully Canada isn't as bad as either place "Yet" you can buy stuff with out the cops showing up, but still idiotic policies at Universities, you can buy every thing but round bottom flasks! LOL some how they magically make the drugs form, not the chemicals!
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[*] posted on 6-5-2016 at 18:14


Back to DCM:
I once got a bottle from my UK supplier, forgot it in a closet for a year and... it was empty when needed.
I ordered a second bottle from the same supplier and transfered the DCM from the HDPE bottle to a Duran bottle with PTFE cap.
I glued a sticker at the limit in the bottle: no change over time.

So yeah, DCM leaks through HDPE without visible evidence. The HDPE bottle was still Inside the plastic bag they ship their bottles in. No trace of the solvent attacking the bag either.

As for keeping the solvents / acids in the fridge I do this based on their vapour pressure and boiling point. With some exceptions though...
I have some dyethil ether in the fridge. I sure as hell wouldnt want my pyridine in the fridge ! The thing stinks even though I have it in glass bottle with PTFE lined cap Inside an ammo box with a seal. I keep this in the toilet (miniature window always open, coolest room in my place) and still it stinks !
Because of this I always Wonder if my toilets are clean. Therefore I clean them very often :)
As for keeping acids in the fridge, I see no point of doing that with H2SO4, very little point of doing that with azeotropic HNO3 (but then, if I lived in Florida or California or any other place that gets very hot in the summer I might think about it) and I never keep >90% nitric acid for more than a few days (Distill it ---> use it)
For some reason I decided to keep my 35% H2O2 in the fridge aswell but I Wonder if there's real value there.
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