Dichloromethane

Discussion in 'Science' started by Goth, Aug 5, 2008.

  1. Goth

    Goth Grumpy Member

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    I want to lay my hands on some dichloromethane, mainly for solvent welding of acrylic and plastics, but for other stuff, too (eg. trying extraction of caffeine from coffee beans).

    Any ideas where I can get it? Anyone know any chemical suppliers that are OK to deal with when dealing with the public? I don't really believe it's a chemical of concern at all with regards to drugs and the like, so I figure it's worth trying if I can find a reasonable chemical supplier.
     
  2. von.Gunst

    von.Gunst Member

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    How much do you need?
     
  3. spazmodik

    spazmodik Member

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    Also known as Methylene Chloride if that helps you find it.

    I wouldn't use it for any coffee that I was going to drink. Just about all major producers ceased using it to remove caffeine once it was labelled as a probable carcinogenic.
     
  4. OP
    OP
    Goth

    Goth Grumpy Member

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    Assuming I'm buying it in AR or LR, I'd probably get a 2.5 L bottle.
     
  5. von.Gunst

    von.Gunst Member

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    Ah, right, you could have been welding your pet battleship or something. As you've probably surmised, buying sample quantities of commodity chemicals may be difficult. It's usually the manufacturer that sells them and they like talking in drums. In order of ease:
    -if you work at or previously worked at a lab, ask them to order it for you. Easy!
    -go to a paint store and ask if they'll sell you some.
    -try talking to BOC. They seem fairly happy to sell canisters of feedstocks, and they've always been reliable in the past, although I'm not sure how public-friendly they are.
     
  6. kwinchee

    kwinchee (Banned or Deleted)

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    I need some to I wanna make Benzocain handy to clean with etc
    Have seen in bunnings at %50,
    But its a solvent, so I doubt its mixed with water not realy foodgrade
     
  7. idosillythings

    idosillythings Member

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    Dichloromethane is not miscible with water.

    I would be careful handling it. Nitrile gloves in a well ventilated area would be my approach. While it is an incredible solvent for many things there could be less toxic solvents that you could use.
     
  8. -KoMoD0-

    -KoMoD0- Member

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    Its fairly easily to find in OTC products, go to a hardware store with a notepad and write down the names of every paint stripper you see and google MSDS sheets when you get home. It wont be pure though.

    Are there any other solvents you could use? I know bunnings sell pure MEK, xylene, toluene and a few others.

    If all else fails give this place a email:

    http://www.austscientific.com.au/

    I have used them before without issue, once I said I wasn't making drugs they happily sold me some mineral acids.
     
    Last edited: Aug 7, 2008
  9. ernie

    ernie Member

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    Try Selby if you get stuck
    http://www.selbybiolab.com.au

    Or even go to Bunnings and read the labels on the plastic adhesives in the plumbing section.

    Sometimes acetone is a suitable replacement depending on the plastic you are trying to weld.

    - Ernie.
     
  10. OP
    OP
    Goth

    Goth Grumpy Member

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    Yeah, yeah, I know. It's a little toxic, and very volatile.

    It's less toxic than chloroform or any other chlorinated hydrocarbon solvent, though.

    For some things, like styrene, yes, but not for acrylic or polycarbonate. It has to be a chlorinated solvent.

    Paint stripper is usually a reasonably high concentration, but distilling it is a major pain in the arse, not the least because of the gummy sticky shit in it, which leaves a residue you can't remove from your good RBFs. And you probably know what it's like trying to buy nice large-ish RBFs these days.

    Pure MEK? You mean MEK without the red dye? Interesting.

    Sure, they sell acetone and xylene, but I haven't seen toluene before, or anything else. More details please.
     
  11. ernie

    ernie Member

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    Most common acrylic is perspex which I thought was made from acetone? http://www.westwardplastics.co.uk/b_acrylic_sheet.php

    The most common Polycarbonate is Lexan, it can be a bugger to glue, I built a kit car once with Lexan windows. You might try using a Spa repair kit as they are often polycarbonate. The good stuff is usually a two part mix called Weldon #40 you can get it from these guys:

    http://www.cityplastics.com.au/adhesives.html

    Probably best to ring em first and describe your application.


    - Ernie.
     
    Last edited: Aug 7, 2008
  12. OP
    OP
    Goth

    Goth Grumpy Member

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    Huh? It's polymethylmethacrylate, yes, i.e. acrylic or Perspex. Contrary to popular belief, it doesn't solvate readily in acetone.

    Yeah, the stuff I want is the water-thin stuff, like Weldon #3, which is basically just straight dichloromethane (though I think it might have just a touch of methyl methacrylate monomer in it.)

    That business looks good, but they're in Adelaide, which is no good to me.

    Cheers.
     
  13. hlokk

    hlokk Member

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    Tried contacting perspex/acrylic fabricators?
     
  14. OP
    OP
    Goth

    Goth Grumpy Member

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    Yeah :) The ones I normally go to to get my acrylic supplies will normally decant off 100 ml or so into a bottle for me, but they don't sell it. That's OK, but you generally burn through it fast because it evaporates so fast.
     
  15. NanoDuke

    NanoDuke Member

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    It's such a coincidence that I found this thread. As I type this I have a scientific journal open with a report showing dichloromethane as the best solvent of choice for dispersing single-walled carbon nanotubes Woo!

    Would dichlorobenzene do the trick? I just got a bottle in for my Honours project. I'm assuming ours came straight from Sigma-Aldrich, though.
     
  16. ernie

    ernie Member

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    Oh yes is does, lot's of people make up a cheapo Perspex glue by dissolving perspex shavings in acetone overnight! Just make sure it's proper acetone not nail polish remover which can be diluted with other things.

    - Ernie.
     
  17. OP
    OP
    Goth

    Goth Grumpy Member

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    Maybe, dunno. I don't think o-dichlorobenzene has anywhere near the same solvent power as dichloromethane.

    Yes, it would be just peachy if I could just go and order whatever I wanted from Sigma-Aldrich, easily, as a private citizen, but I don't know that I can. :)
     
  18. Daveboy

    Daveboy Member

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    You used to be able to buy things from Crown Scientific if you were an average joe, don't know if you still can
     
  19. -KoMoD0-

    -KoMoD0- Member

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    Bunnings should stock the whole Diggers range, if they don't have it there you should be able to get it from their 'special' orders desk. The MEK I saw was in the plumbing section, it was a clear primer. Don't quite remember the concentration but I think it said 1000g/L, chances are its pure MEK with some water.

    As to decent flasks, there are quite a few stores in the US who will happily ship our way.

    Crown Sci wont talk to anyone if they don't have a ABN, that goes for 95% of scientific suppliers.
     
    Last edited: Aug 7, 2008
  20. SenorGrande

    SenorGrande Member

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    I've seen toluene in Bunnings before... comes in small tins iirc. Its in the solvent section, which is usually near the expanding fillers etc. They also have a fair few other solvents as well.
     

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