Sciencemadness Discussion Board

Copper & PVC

Chemicals - 19-5-2006 at 05:26

I'm looking for a chemical which can dissolve pvc (soft)(melting point 180° C) and yet not attack copper. The copper is insulated in a pvc tube and I am in need of separating the two by a chemical reaction.

12AX7 - 19-5-2006 at 05:32

Well, that won't be very hard, will it?

A lot of THF or cylcohexanone or whatever PVC solvent is best should do it, no? Of course you'll have to do a lot of washing to get clean copper since the solution is sticky.


Chemicals - 19-5-2006 at 06:03

thanks...will give it a shot and get back with results

Chemicals - 19-5-2006 at 06:32

how lond do I have to leave the solution for the effect to take place?

DrP - 19-5-2006 at 06:53

"how lond do I have to leave the solution for the effect to take place? "

It depends on the solvent you are using and the molecular weight of the plastic. Soak it in some acetone for a few mins and see if it has lossened - if so then scrape it off and wipe it with clean with some fresh acetone (or THF or whatever). If it hasn't had much effect then leave it for another 10 mins, half hour, 1 hour or as long as it takes (overnight even) to soften/dissolve - then clean it off. If it is slow then you could try scratching the PVC, scoring it up so the solvent can work its way in easier (effectively increasing the surface area of the plastic - thus more sites for solvent to attack)

If all else fails - can you use a blow torch to burn off the plastic and then clean the copper?

Chemicals - 19-5-2006 at 08:49

the acetone had no effect.........

neutrino - 20-5-2006 at 14:52

What you want is a good chemical resistance chart like this one or this one. Look at the chemicals you have available to you and find which solvents dissolve / destroy PVC.

IrC - 20-5-2006 at 15:50

Methylene Chloride. CH2Cl2

Chemicals - 22-5-2006 at 04:09

Thanks IrC...will give it a try. The only effect from first suggestion is that the PVC was softened. But it did not dissolve it as I wished. The object is as follows: I have a cable with isolated copper inside. second scenerio is that there is isolated alluminum.....rather than melting I am looking for a chemical reaction to attack the pvc in a non toxic form and not attack the copper or alluminum element. I am using large containers for the process

Chemicals - 23-5-2006 at 06:10

IrC....why did you suggest CH2CI2 when according to the chart it is not recommended for PVC? What do you suggest I use??????

IrC - 23-5-2006 at 07:24

You are joking right? Look at your question again. CH2Cl2 is not recommended as it dissolves PVC and the chart is titled "chemical resistance". You don't want resistance, you want to get the PVC off the metal. CH2Cl2 does not affect the metal.

However it is not non toxic. Breathing the fumes will kill you. Skin contact will kill you. CH2Cl2 produces carbon monoxide in your bloodstream, and also causes cancer. I used to use it to depot electronic black boxes. A container of it in the sun will explode from vapor pressure, you have to keep it cool and in the dark. Not a fun or safe chemical to play with. Then again, nothing that will do what you want is going to be safe anyway.

Chemicals - 23-5-2006 at 07:31

....thanks.....sound like a nice toy for July 4th........any other suggestions for a non-toxic chemical..........anyhow thanks for the help

DrP - 23-5-2006 at 08:23

"The only effect from first suggestion is that the PVC was softened"

If the THF softened the material then surley it is starting to dissolve - as I said you may even need to leave it over night, from the times on your posts you left it a maximum of 2 hours. The list also indicates that PVC isn't resistant to THF. Once it softens, scratch the stuff up and leave it to soak for longer.

[Edited on 23-5-2006 by DrP]

Chemicals - 24-5-2006 at 07:17

Hey what ya know!!!! It worked!!! Thanks DrP!!!

Archimede - 3-6-2006 at 07:42

Are you trying to cut into some electrical feeders to a building?

Mr. Wizard - 3-6-2006 at 14:09

Originally posted by Archimede
Are you trying to cut into some electrical feeders to a building?

I'll bet he is trying to remove insulation from scrap copper wire. I got five hundred pounds of wire myself a few weeks ago in a bonanza dumpster dive. I started to peel it by hand myself but it was too much work for another few hundred dollars. I let it go for much less with the insulation on it. Burning it would have left a toxic cloud and wouldn't be practical for that much wire. You can't get it all.