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PTFE degradation with water and heat

I am a student doing a six-month placement in a coating company. We are working with non stick coatings and their formula include PTFE. The coated piece is used to boil water. We observed that after a certain amount of boiling cycles, the PTFE seems to degrade. Is it possible? Have you ever heard that PTFE could degrade in presence of water and heat (up to 450 degrees C)?

Celine Rigaud
student - Gateshead, Tyne and Wear, UK
2005

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1st of two simultaneous responses--

I think at 450°C even PTFE isn't stable any more.That is easy to find out, just ask the supplier or look in a material datasheet.

Marcus Hahn
- Lucerne, Switzerland
2005

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2nd of two simultaneous responses--

PTFE will degrade on heating to above about 350 C. This is well documented in the web, so it is worth a check. The actual degradation products depend on the temperature reached and some of them can be quite toxic. The most common problem with degrading PTFE is "PTFE flu"; it is a flu-like illness that will go away when you stop inhaling the fumes. However, I am intrigued as to how you will get PTFE up to 450 °C in the presence of water; surely the maximum temperature you can get with water is 100 C, unless you use superheated steam of course.... You may get localised hot spots, but the thermal capacity of water is such that it should dissipate any excessive heat and maintain 100 C.

Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK
2005

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2005

Hi Celine,

Trevor hit the nail on the head. How in the Hell can you heat up a Teflon coated vessel containing water to 450 degr C ?

You can't ...or the vessel is empty in which case the temperature is far too high and, unless you wear a mask or
better still a breathing apparatus, you'll regret you didn't do so.

Are you sure it's PTFE? What about other fluorocarbons? Didn't the UK invent a polymonochlortrifluoroethylene?
Don't take it as gospel what others say to you ... we are
human and ... tend to err, sometimes.

Freeman Newton [deceased]
(It is our sad duty to advise that Freeman passed away
April 21, 2012. R.I.P. old friend).

I want to get some information about degradation temperature of PTFE.

Ibrahim Anwar Hassounah
- Aachen, Germany
2006





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