Sciencemadness Discussion Board

Easy source or synthesis of formaldehyde

SimpleChemist-238 - 29-9-2014 at 17:25

hello I have a simple question on a easy OTC source of formaldehyde. I don't want to go online to get it but I was hoping someone knows a store bought solution. I already checked a wiki list on easily found chemicals list and it was not available.

Maybe someone had a easy source or a easy way to make it. thank you.

Steam - 29-9-2014 at 17:36

May this answer your questions!

http://www.sciencemadness.org/talk/viewthread.php?tid=13281

Tdep - 29-9-2014 at 20:27

It is sold under the brand name 'Formalin' as a disinfectant, maybe only to industry however. Although it may be harder to find these days, my grandma used to run a vet practice and still has litres of this 40% or so solution of formaldehyde lying around. Also talk to med students. They love the stuff, and I know they still use it as a preservative, at least in Aus.

Speaking of which, if any one can think of a cool thing to do with heaps of formaldehyde? Organic chem isn't my thing though

plante1999 - 29-9-2014 at 20:36

plastics, pentaerythritol, methylamines etc

UnintentionalChaos - 29-9-2014 at 21:14

You should be able to make some quite pure hexamine with aqueous ammonia. Not that it is super useful, but you go from two liquids to crystals of an elaborate cage structure compound.

Tdep - 29-9-2014 at 21:19

It would be cool to see hexamine precipitate (right word?) out of a mixture of two gases. I assume the reaction would look like HCl + NH3?

Chemosynthesis - 29-9-2014 at 22:58

Prec
Quote: Originally posted by Tdep  
It would be cool to see hexamine precipitate (right word?) out of a mixture of two gases. I assume the reaction would look like HCl + NH3?

Precipitate would be the correct term for a gas phase reaction (and industrially used along with solvent phase reactions), but your reactants would need to be ammonia and formaldehyde, as there are 6 carbons per four nitrogen in each molecule of hexamine.

Tdep - 29-9-2014 at 23:10

Oh yes, when I said 'look like' I meant that in a pure physical way, where two gases form what looks like a white smoke that is actually a very fine solid.

I've done this sort of reaction with HCl + ammonia and it was rather nice, so I was just wondering whether the formaldehyde and ammonia gas phase reaction would look very similar to this.

I already have hexamine, but pentaerythritol sounds interesting. You people are never short of ideas

SimpleChemist-238 - 30-9-2014 at 03:40

maybe using a acidic catalyst I can make it from Hexamethylenetetramine. Would the ammonia evolve from the acid or react with it and then so would distillation work well for separation. I could use sodium bisulfate as the acid so it would not be a liquid or quite as expensive as H2SO4. but there is still a chance of getting water over in the distillate. but there would be very little.

bismuthate - 30-9-2014 at 03:50

I believe that, if you've ever seen a preserved shark carcass souvenir (probably more popular here in an on the water tourist town), they are put in formaldehyde.

Praxichys - 30-9-2014 at 04:40

You can make it by running methanol through a very hot copper coil.

https://drive.google.com/file/d/0B_16NzkNoL75T054RHMyNlBzVDA...

I usually buy it because that process is pretty tedious. I got this on ebay:

The apparatus above can also produce acetaldehyde from ethanol, which was its primary use.

Endo - 30-9-2014 at 05:49

Maybe try either using Trioxane (purified from fuel tablets) or de-polymerizing it by using a strong acid.

http://www.sciencemadness.org/talk/viewthread.php?tid=14739
Discusses the trials with conversion to formaldehyde and the purification of Trioxane.

chemrox - 30-9-2014 at 08:33

I love the homebake burner. Could you describe it?

Scr0t - 30-9-2014 at 10:11

In the farm centers here it can be bought by anyone for ~30 euro for 25L, it's not considered a 'suspicious' chemical.

SimpleChemist-238 - 30-9-2014 at 10:29

Thank you for the info. The Trioxane methode sound intresting

Praxichys - 30-9-2014 at 10:59

@chemrox -

The burner is pretty simple. It is made entirely of 1/2" standard iron pipe.

The galvanized base has a plug threaded into it. The plug was hammered into the gas inlet T and welded in place to form a gas-tight seal. Epoxy or even silicone could probably also work.

The T has a hose barb threaded into it with thread tape. The top of the T has a plug threaded into it. The plug has a hole drilled through it to form the gas jet.

The second T is hammered and welded onto the gas jet plug. The sidearm of this functions as the air inlet. Various attachments can be threaded into the top to change the flame width. I have attachments all the way up to 2 inches.

The issue with this burner is that it does not work all that well at low settings. It is good for this application since high heat and a large, wide flame is ideal... but for smaller heating applications, the flame tends to jump into the body of the burner itself at low gas pressures.

Anyway, the threaded side inlet can accept another hose barb and was designed to be attached to an air compressor. This works well and gives a hellishly tall and roaring flame. This feature is rather useless since it is quite inappropriate for indoor applications.

SimpleChemist-238 - 30-9-2014 at 11:05

How did you make the coper coil? It seems like a ok method.

[Edited on 30-9-2014 by SimpleChemist-238]

Formaldehyde and Sharks

katgirl2000 - 30-5-2016 at 07:49

Quote: Originally posted by bismuthate  
I believe that, if you've ever seen a preserved shark carcass souvenir (probably more popular here in an on the water tourist town), they are put in formaldehyde.


Hi!
First post here. The preserved shark reference made me chuckle. I'd bet anyone who took 1st yr bio for majors would have the same instant response as me. My class was so long ago that you had to fight dinosaurs for parking but dissecting the brain for a week coming home at night with dandruff composed of preserved shark cartilage - perfect olfactory aura!

I've been wanting formaldehyde for dissections I've done here but my main interest is on the energetic floor.

Best!

100PercentChemistry - 30-5-2016 at 09:10

I've seen a couple of videos on YouTube like a copper coil or ketone lamp. At a beach suveneer shops they sell these puffer fish and sharks in a jar like you guys said but there are pieces of tissue floating around I would just filter it.mProbably formaldehyde

[Edited on 5-30-2016 by 100PercentChemistry]

Dr.Bob - 31-5-2016 at 12:05

You can actually just go to the local mortuary supply shop. :-) I have actually been in one before.

Orenousername - 3-6-2016 at 01:08

I have been trying to convert broken/melted keck clips, which I believe to be polyoxymethylene, into formaldehyde solution (because why not) but I have not been able to find information on the solubility of formaldehyde vs temperature. I figured since formaldehyde is a gas, it's probably more soluble in cold water, but wikipedia states that paraformaldehyde is more soluble in hot water (?). I simply cut the keck clips into pieces and put them in a copper tube and heat it with a torch, then bubble the produced gas into cold water, but the resulting mixture is yellow and has a lot of white solids in it (paraformaldehyde?) The gases are very irritating and smell plasticy, but I am not familiar with what formaldehyde smells like, would any of you care to enlighten me?