[xchcui]

Hi.

I have an old black cooling hose(part of car cooling system)which made by general motors at around the years 1988-1990.
I know that cooling hoses can be made from silicone,epdm,neoprene and butyl rubber.
At those years.i don't think that GM used silicone rubber for coolant hoses and i am not sure about epdm.
So,i think that the coolant hose made from neoprene or butyl rubber.
Is there any quick test,without special equipment or special materials,which i can identify if the coolant hose made of neoprene or butyl rubber?

Thank in advance.

[Enthalpy]

If you have surely identified samples of the candidate materials AND you can take a sample from the part, one excellent method is to burn them and compare the smell. Even the human nose distinguishes many polymers like that. The aspect of the flame tells also much.

Isoprene should smell like polyolefins (polyethylene, polypropylene...) which remind of candles, but the chloride-containing isoprene will be very different, supposedly similar to polyvinyl chloride.

Please burn small amounts and not in your closed kitchen. Burning Pvc is nasty for real. Near you nose slowly, no more than needed.

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The second method is the density. Neoprene is clearly denser than water (>1230kg/m³) and sinks. Butyl rubber is mainly a polyolefin, with density around 920kg/m³ so it floats on water. Eliminate all air bubbles for the test.

That would be for pure formulations... Rubbers are often blended.

[xchcui]

Thank you very much for your help.
It was a great explanation about the two rubbers
and how to make the test.
It seems that the second option is easier to do,but i will try them both,since,as you mentioned,the
coolant hose might be blended and i should take it into account.
Thanks again.