Sciencemadness Discussion Board

Is vulcanizing latex reasonable to DIY? Are there OTC chemicals to do it?

Junk_Enginerd - 27-7-2021 at 11:06

I want to do some experimentation with latex and rubber. To make useful things with latex, it's usually necessary to vulcanize it. What are the most accessible chemicals that can be used for the purpose?

I tried it with just sulfur and various types of heating because why not, but not much happened, which was expected really. According to wikipedia vulcanization with just sulfur works, but takes a very long time, and that seems to be right...

Apparently there are a bunch of chemicals that accelerate/catalyze the action of sulfur on the rubber, which is how it is done industrially. A bunch of them were listed on wikipedia but I didn't recognize any of them.

I'm hoping those catalysts are just the optimal industrial ones, and that a more common chemical could be used in their place. Does anyone here know of such a chemical or a process of vulcanizing rubber that is mostly OTC?

As for my intended applications I'm experimenting a bit with slingshots and thinking vulcanizing could provide some new possibilities. It'd also be interesting to try to make solid hard rubber parts etc.

Triflic Acid - 29-7-2021 at 05:55

Try sulfur chlorides. There is a prep somewhere here on using for rubber vulcanization.

Junk_Enginerd - 31-7-2021 at 03:39

Yeah I found some info on sulfur chlorides. The synthesis seems simple enough, though finding information on its application certainly wasn't... Well, I was on the fence about giving it a go, but now I think I will. Thanks.

Edit: I understand that the function of the chlorine is mostly to act as a solvent for the sulfur. If it's just a sulfur solution that is wanted, could one use any other solvent as well? Sodium hydroxide solution comes to mind.

[Edited on 31-7-2021 by Junk_Enginerd]

karlosĀ³ - 31-7-2021 at 03:48

Sulfurylchlorides are not a solution of sulfur in chlorine, its a covalent bonded molecule.

zed - 31-7-2021 at 20:12

Jewelers Sometimes use a machine called a Vulcanizer. They use it for mold-making. Thin sheets of Latex rubber are fused together utilizing heat and pressure. An alternative is a two part silicone rubber casting material, that works pretty well.

In days of yore, These Silicone casting rubbers lacked the strength and durability of Vulcanized Latex. I don't know if current Silicones are any better.

Latexes are more sophisticated than they used to be.

I don't remember Latex of old, being so pliant.

I would imagine, you can improvise the vulcanizing machine, utilizing materials on hand.

[Edited on 1-8-2021 by zed]

[Edited on 1-8-2021 by zed]

Junk_Enginerd - 2-8-2021 at 02:15

But that video does not even mention the use of any chemicals. Is it just heat and pressure then? I assume that doesn't change the rubber hardness either.

zed - 2-8-2021 at 02:33

Yeah. No chemicals required, other than those already present in the latex sheets. The sheets themselves however, seem to be available in a variety of different "hardnesses".

Junk_Enginerd - 17-8-2021 at 03:34

Quote: Originally posted by zed  
Yeah. No chemicals required, other than those already present in the latex sheets. The sheets themselves however, seem to be available in a variety of different "hardnesses".

No, this isn't vulcanizing. Just bonding. I tried it, and while it's definitely a useful method to bond rubber I can't agree that there's any vulcanization happening.

I tried it with S2Cl2 though, and holy balls that's an aggressive chemical. It vulcanized any rubber it came in contact with in a couple of seconds. It's a little too aggressive to be practical tbh. It's basically like scorching the rubber with a blowtorch, and as such vulcanizes too much on the surface and has trouble penetrating much deeper than <0.5 mm or so. Probably need to dilute it somehow.