Talk:Polytetrafluoroethylene

What makes it stick to the frying pan?
I came here to find that out, and I don't see it on the main page. This could one of those "universal solvent"-type questions but it might have a simple answer. I'm guessing an intermediate layer of something with a bond to the carbons on one side and to the steel on the other....--Hugh7 (talk) 08:20, 4 November 2010 (UTC)

The Skinny On... Why Teflon Sticks to the Pan by Hannah Holmes at discovery.com. Senator2029 &#124; talk &#124; contribs 13:29, 31 August 2011 (UTC)

shape vs. chemical structure
The 'picture' of PTFE is of a kinked line. For that structure to exist, the chemical formula would need to include some C=C (carbon-carbon double bonds). However the chemical structure given suggests that the carbon structure is saturated with fluorine?--Ryan Wise (talk) 17:54, 30 May 2010 (UTC)
 * I think the point is that it's a flexible chain - the picture below the structure is perfectly compatible.Lexyboy (talk) 14:43, 27 August 2010 (UTC)

Space plan thingy
Do we need to mention about the fact that supposidly Teflon was a by-product of the space programme?  ' The Ninja  lemming '  18:23, 24 February 2009 (UTC)

Given that anyone reading the article can see that PTFE was patented in 1941, there's probably no need to mention something so obviously false. —Preceding unsigned comment added by 212.188.147.34 (talk) 13:09, 14 July 2009 (UTC)

Category for accidental discovery / inventions
It is interesting that it was invented as the result of a accident. What other compounds have been so invented or discovered? Would it be worthwhile to have a category for this? SlowJog (talk) 13:59, 26 June 2009 (UTC)


 * Lots are, it would be a very, very large section. 82.132.139.215 (talk) 17:29, 18 September 2009 (UTC)


 * Or a alphabetical list. If needed, it could be distributed on on several pages. SlowJog (talk) 02:33, 27 September 2009 (UTC)


 * I did not mean to suggest a section on accidental inventions be added to this article. I meant to suggest a Wikipedia category be created (if there isn't one already), and this article linked to the category. SlowJog (talk) 15:27, 22 May 2010 (UTC)

ICI (Imperial Chemical Industries)
Why is there no mention of ICI and "Fluon" in this article? Ksmill (talk) 14:24, 3 September 2009 (UTC)

Guessing for the same reason there's little mention of Dyneon, and none of Daikin or other manufacturers. —Preceding unsigned comment added by 212.188.147.34 (talk) 10:55, 7 January 2010 (UTC)

Teflon Death
How much of this article is true? Any of it that's true deserves to be in Wiki:

http://www.ecomall.com/greenshopping/teflon4.htm


 * Is this source a reliable source (see WP:RS for info on what is a reliable source). Reading the link, I would say no it isn't.  However if there are other sources which have similar info (say from newpapers) then this info is worth examining.  Shot info (talk) 05:42, 8 March 2010 (UTC)

There are lots of them. here are two: http://www.backyardpoultrymag.com/warning_teflon-coated_light_bulbs_toxic_to_chickens_the_full_story/ http://www.rachelcarsoncouncil.org/index.php?page=pet-birds-harmed-by-non-stick-coating-fumes Arydberg (talk) 19:54, 18 June 2015 (UTC)

Safety: single point of view
I have marked section "Safety" as disputed. It only demonstrates one point of view. Please consider stating opposite claims and studies. Ahmediq152 (talk) 15:57, 13 October 2010 (UTC)
 * I removed the tag because you did not cite any "alternate" studies why they conflict with the section. Please explain before tagging again thanks. -Shootbamboo (talk) 21:25, 13 October 2010 (UTC)

Thermolon
See also: "Harmful Teflon Chemical To Be Eliminated by 2015". Can anybody explain how Teflon compares to coatings like Thermolon? —Preceding unsigned comment added by 85.223.52.7 (talk) 20:17, 11 March 2011 (UTC)

Safety: an ancient & mysterious study says teflon is safe to burn on its own
I removed the last paragraph of the "Safety" section which stated "A 1959 study (conducted before the U.S. Food and Drug Administration approved the material for use in food processing equipment) showed that the toxicity of fumes given off by the coated pan on dry heating was less than that of fumes given off by ordinary cooking oils." An uncited study which is over 50 years old and seems to partially contradict with what is stated just above it does not belong here 27 April 2011 - StevenBee

Cancerogenic concerns and class action suits against Teflon manufacturers
There's nothing in the article about public suspicion that Teflon can be cancerogenic (the word cancer is only one and hidden in the hame of 18th reference) and about last judicial trials against most Teflon manufacturers. Such information need to be added for the full picture of this material. Also there's already many alternative materials to Teflon - i found three of them: Bio-Lon, Thermolon and Ecolon. Westsomething (talk) 05:37, 2 December 2011 (UTC)

Conformation


It's well-documented in the scientific literature that PTFE chains adopt a helical conformation, but this isn't mentioned in the article. I think it's a simple, interesting point that has an effect on the physical properties of the polymer (several order-disorder phase transitions around room temperature). I'm not an expert in polymers or PTFE, so I'm floating the idea here first. Which section should it go in?

I've updated the 3D diagram in the infobox - it's actually of a perfluorodecyl chain in a medium-sized organic molecule, but it has the same helical conformation as PTFE and is an experimentally determined structure (single crystal x-ray diffraction).

Here are some references:
 * "The molecular conformations of polytetrafluoroethylene: forms II and IV", E. S. Clark, Polymer (1999) 40, 4659–4665
 * "Modeling of helix reversal defects in polytetrafluoroethylene: II. Molecular dynamics simulations" D. B. Holt, B. L. Farmer, Polymer (1999) 40, 4673–4684
 * "Conformational and orientational order and disorder in solid polytetrafluoroethylene", M. Sprik, U. Rothlisberger, M. L. Klein, Mol. Phys. (1999) 97, 355–373
 * "Periodic and high-temperature disordered conformations of polytetrafluoroethylene chains: An ab initio modeling", M. D'Amore, G. Talarico, V. Barone, J. Am. Chem. Soc. (2006) 128, 1099–1108

There's a good, brief summary of the current state of knowledge on PTFE conformation and phase transitions in [http://dx.doi.org/10.1021/jp9093035 ''J. Phys. Chem. A'' (2010) 114, 1118–1122].

Also discussed at Alkane stereochemistry, which cites [http://dx.doi.org/10.1021/ja0602041 ''J. Am. Chem. Soc.'' (2006) 128, 6000–6001].

Ben (talk) 23:50, 27 December 2011 (UTC)

50,000 hits per month
This thing is a very high view topic. Wish we had a GA. 10 years into this thing and a lot of fundamental content is not done. I keep finding more stuff to do as I work on one article...it is all connected.TCO (Reviews needed) 01:32, 1 January 2012 (UTC)

I proposed a separate article on ePTFE
Or at least a section!

What we have now is way skimpy. And the Gore-tex page is not appropriate since it is about a fabric laminate, and a PU/PTFE membrane, not the ePTFE.

TCO (Reviews needed) 23:30, 2 January 2012 (UTC)

"Safety" section needs re-writing
This section needs to be rewritten to include that this chemical is not safe, especially in light of recent court proceedings against DuPont. This chemical has been linked to prostate cancer, birth defects, and respiratory infections. Studies by DuPont have proven that there is no safe level of consumption of this poisonous chemical. Please see: http://highline.huffingtonpost.com/articles/en/welcome-to-beautiful-parkersburg/?ncid=fcbklnkushpmg00000063 — Preceding unsigned comment added by 172.8.146.166 (talk) 22:01, 30 August 2015 (UTC) PAGE ]]) 02:58, 4 April 2022 (UTC)
 * The information in the "Safety" section seems more or less okay, but the presentation is a bit garbled. It needs to be re-written.  — Preceding unsigned comment added by 108.20.253.150 (talk) 04:06, 6 June 2012 (UTC)
 * That article says that C8, aka Perfluorooctanoic acid, is toxic. Polytetrafluoroethylene, which is what this article is about, is not. --Ahecht ([[User talk:Ahecht|TALK

Radiometry/Optical Properties
The section on uses, radiometry mentions the use of PTFE for optical diffusers. A very important point that is not mentions is the fact that PTFE has a room temperature (19 C) phase transition that affects its optical transmission and electrical properties. For uses a diffusers in the near UV the effect is an approximately 2% change in the transmission.

http://dx.doi.org/10.1016/j.optmat.2004.11.008

http://dx.doi.org/10.1109/NSSMIC.1991.258937

http://www.micro-coax.com/pages/technicalinfo/applications/27.asp

http://dx.doi.org/10.1021/j100013a035 — Preceding unsigned comment added by 67.161.253.189 (talk) 16:40, 9 June 2012 (UTC)

Not sure how to add a reference (yet)
But there is a source for one of the "citation missing" statements.

http://www.sealing.com/fileadmin/docs/Using_Bellville_springs_to_maintain_bolt_preload.pdf

"Sometimes metal springs are used to apply continuous force to PTFE seals, giving good contact while permitting a beneficially low percentage of creep.[citation needed]"

454Casull (talk) 14:01, 16 May 2014 (UTC)


 * I put it in as currently Reference 21. The "Citation needed" tag was taken out.  H Padleckas (talk) 04:21, 18 May 2014 (UTC)

Applications section
The Applications section needs references to compare industrial and consumer-cookware uses to eliminate the "other" paragraph. Because cookware doesn't actually use much polymer? Is cookware an application where the polymer is created in-place, thus not made by chemical company and shipped to them?165.121.80.222 (talk) 18:26, 21 July 2014 (UTC)

Record-low conductivity?
Of the materials listed in the Electrical Conductivity article, Teflon has the lowest conductivity. But it's not a comprehensive list of all materials. Is there another material with even lower conductivity?

If Teflon has the lowest conductivity of any known material, that's a pretty notable property that should be mentioned in the article. 75.163.166.82 (talk) 15:22, 9 August 2014 (UTC)

Low resistance against flowing liquid ???
I have just removed (from the article) the following paragraph:
 * Another major application is in fuel and hydraulic lines, due to PTFE's low resistance against flowing liquids. Colder temperatures at high altitudes cause these fluids to flow more slowly. Coating the lines's interior surfaces with low-resistance PTFE helps to compensate by allowing the liquids to move more easily.

This statement was attributed to Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim. , but in this form it is completely false. The author must have confused hydraulic/hydrodynamic resistance to flow with chemical resistance, which is the most important reason of using PTFE in tubings and hoses. Low friction of teflon has nothing to do with the case of flow of liquid - at least as long as the diameter of the tubing is much largar than of the order of several hundred nanometer. The flow rate of pressure driven laminar flow of any liquid in a tubular pipe is given by Hagen–Poiseuille equation and the assumption of no-slip condition is always valid for liquids in the macroscopic scale. If this is not enough, the hypothesis of "low resistance of teflon against flowing liquid" was explicitely falsified by scientific experiments over 50 years ago - Journal of Research of the National Bureau of Standards, Vol. 58, No. 1, January 1957. Research Paper 2734. Resistance of Flow in Teflon and Brass Tubes,, and there is the link. I can agree that PTFE is widely used in hydraulic and fuel lines, but the reasons are completely different than "allowing the liquids to move more easily". Tescobar (talk) 16:26, 2 September 2014 (UTC)

unstable monomer
The decomposition into CF4 and C is unlikely to be the initial reaction in the exothermic reaction of TFE monomer. explosive polymerization of bulk monomer is a well documented phenomena with alkene monomers. For example, styrene explosive polymerization has 2 million hits on google search. As the TFE runaway polymerization proceeds and temperature and pressure build, the reaction may change to that which forms CF4 and carbon. TFE is usually polymerized by emulsion polymerization in water to control heat buildup and limit viscosity to prevent poor heat transfer. — Preceding unsigned comment added by 66.194.206.214 (talk) 11:26, 25 March 2016 (UTC)

low surface energy
Dry_lubricant says it has low surface energy but its not mentioned here. - Rod57 (talk) 10:59, 13 August 2017 (UTC)

seemingly conflicting content in the article as currently written.
I have little understanding of chemistry and am reading to learn more and found the following confusing:

In the "History" section it says:

"In the 1990s, it was found that PTFE could be radiation cross-linked above its melting point in an oxygen-free environment.[16] Electron beam processing is one example of radiation processing. Cross-linked PTFE has improved high-temperature mechanical properties and radiation stability. This was significant because, for many years, irradiation at ambient conditions has been used to break down PTFE for recycling.[17] This radiation-induced chain scission allows it to be more easily reground and reused."

But then in the "Properties" section it says:

"Because of its chemical inertness, PTFE cannot be cross-linked like an elastomer."

Can PTFE be cross-linked or not? Maybe there are different kinds of cross-linking and that could be clarified in the text in those two places.

thank you. 2601:1C2:600:EF6:A8E5:71E:1F69:DEFC (talk) 21:15, 31 December 2018 (UTC)
 * Very good question. I'm not a chemist either. Have you read ref #17? --Quisqualis (talk) 07:08, 1 January 2019 (UTC)

PFOA section?
Why is there a PFOA section in this article? These are different chemicals. Ratel (talk) 03:21, 9 May 2019 (UTC)
 * This struck me as odd as well. I think a sentence mentioning its use as a surfactant in the manufacturing process along with a reference and a wikilink to the main PFOA article would be appropriate.  Everything else may belong in the PFOA article, but is out of place here.MDK33 (talk) 17:15, 7 February 2020 (UTC)

PFOA is referenced I believe because the main source location for the discovery of the problems with PFOA were a Du Pont production facility for Teflon on Ohio, as documented in the PFOA page. This led to large settlements for thousands if individuals who suffered illness and/or died. Moreover, it is the source of the world-wide movement towards radical reduction in the use of PFOA or its total phasing out. However, it will also require balancing accounts. I don't know if all Teflon production was or any is a source of PFOA pathologies or whether Teflon coated cooking equipment might become problematic after extended use. I consider that cross reference to the contamination caused at a Teflon plant is justifiable. This implies that each Teflon plant needs to have had inspections that properly clear it from similar cases in order for production to now be considered safe. PFOA has been phased out in many cases since 2015. The situation with cookware still should be investigated and reported with the requisite citations. — Preceding unsigned comment added by Maven111 (talk • contribs) 23:41, 10 February 2021 (UTC)

You can also read more about it in this The Guardian review. The Guardian is one of the 4/5 leading UK "quality" as opposed to "tabloid" newspapers, owned by a foundation. Teflon is closely associated with PFOA, and the family of related synthetic chemicals. — Preceding unsigned comment added by Maven111 (talk • contribs) 23:58, 10 February 2021 (UTC) Maven111 (talk) 00:15, 11 February 2021 (UTC)

This wiki has quite a biased anti-regulation position.
Really there shouldn't be any references to 'fact sheets' from industries like the wastewater industry that has taken a strongly anti-regulatory position (see ref 60, for example, and for the lobbying efforts and spending by this industry, . — Preceding unsigned comment added by 75.174.217.203 (talk) 21:41, 24 August 2020 (UTC)
 * I agree with you and I've removed the text. Tell me if there is more. Ratel 🌼 (talk) 03:06, 25 August 2020 (UTC)

dispersion
Another characteristic of PTFE of great significance is that the dielectric constant (the electrical equivalent of optical index of refraction) does not change over a very wide range of frequencies. That is, as an insulating medium, it has very little dispersion. Thus wide bandwidth signals can propagate without delay distortion caused by differences in speed of propagation with frequency. I know I need a reference, but I believe this because, for years, I would see an add from a company that made teflon capacitors that included a graph showing the lack of dispersion. --AJim (talk) 15:57, 22 September 2020 (UTC)
 * You're correct. I remember in the 1980s I worked in a microwave materials characterization lab. We used reflectometers and transmissions systems to characterize the dielectric constant and loss tangent for various materials (or the effective constants for composite materials). We measured teflon's dielectric properties as flat across the spectrum from 2 to 100 GHz (the range of equipment we had); about 6 frequency octaves. For a dense solid, PTFE has an unusually low dielectric constant of of about 2.0 and negligible loss. ~Anachronist (talk) 19:23, 22 September 2020 (UTC)

"Teflon®" listed at Redirects for discussion
An editor has identified a potential problem with the redirect Teflon® and has thus listed it for discussion. This discussion will occur at Redirects for discussion/Log/2022 April 15 until a consensus is reached, and readers of this page are welcome to contribute to the discussion. BD2412 T 05:07, 15 April 2022 (UTC)

Isn't wikpipedia supposed to be for the average reader? Why doesn't this article use the common and familiar title of 'Teflon'? If you were to ask 1000 people what polytetra-bla-bla-bla is, you would be LUCKY if you found 'one' who knew. The chemical name should be a footnote, not the title in an article for the average reader. I see this done a lot on articles on plants and minerals, etc. Where are Wikipedia's priorities at? For the common reader or lay person, or for professional scientists who don't even consult wikipedia? — Preceding unsigned comment added by 107.77.231.37 (talk) 09:45, 26 April 2022 (UTC)

"Forever chemicals"
Why is the term "forever chemicals" not mentioned even a single time in the current version of this article? 173.88.246.138 (talk) 23:54, 5 June 2022 (UTC)


 * I was thinking the same - the whole article looks like an advertisement, heavily downplaying or ignoring the problems, like DuPont's documented chronic lies. I'll need to do more research on this. 2001:7D0:8412:5D80:AC26:B124:510:7118 (talk) 11:45, 30 June 2022 (UTC)

Requested move 28 October 2022

 * The following is a closed discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. Editors desiring to contest the closing decision should consider a move review after discussing it on the closer's talk page. No further edits should be made to this discussion. 

The result of the move request was: not moved. (closed by non-admin page mover) — Ceso femmuin mbolgaig mbung, mellohi! (投稿) 22:46, 4 November 2022 (UTC)

Polytetrafluoroethylene → Teflon – Per WP:COMMONNAME. PhotographyEdits (talk) 21:18, 28 October 2022 (UTC)
 * Support per WP:COMMONNAME. It already directs here, so it's clearly the primary topic. This seems analogous to other articles where a brand name has become so overwhelmingly used, that it has become a generic name, such as Aspirin, Frisbee, Bubble wrap, Hula hoop, Lava lamp, and Dumpster. Rreagan007 (talk) 23:32, 28 October 2022 (UTC)
 * Oppose: Per WP:ENGVAR, the acronym PTFE is commonly used in the UK, for example in plumbing for PTFE tape. YorkshireExpat (talk) 17:21, 29 October 2022 (UTC)
 * WP:ENGVAR does not apply here, as this isn't a case where "Teflon" is the American term and "PTFE" is the British term. "Teflon" is used in British English too. Here is the BBC using it. Rreagan007 (talk) 04:20, 30 October 2022 (UTC)
 * The BBC is a global broadcaster and Aaron Heslehurst, the presenter in the video, primarily appears on the BBC World Service. I'm not saying Teflon is never used, but I would suggest that most people wouldn't know they are the same thing, hence this sort of article existing, but if you would like a list of UK suppliers who use the term PTFE, then there you go.
 * Hence it makes sense to me to use the unambiguous full chemical name with suitable redirects. For your list of genericised trade marks, most of them I would agree with from a UK perspective, but defintely not dumpster, and probably not hula hoop! I also guess that Tannoy isn't used in the US the same way as it is in the UK. YorkshireExpat (talk) 09:00, 30 October 2022 (UTC)

The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.
 * Oppose. The trademark has been somewhat genericized, but not to the point that it should replace the current article title.  The primary redirect is just fine. 162 etc. (talk) 17:10, 30 October 2022 (UTC)
 * Oppose - Teflon is used for multiple materials, including (but not limited to) PTFE, FEP, PFA, and TFE. This applies both to the trademark and to shorthand (e.g. the encapsulation on "Teflon-encapsulated o-rings" is often an unbranded FEP shell). So both the proposed change and the current Teflon -> PTFE redirect are problematic.2600:1001:B019:4394:5D51:FF27:8FB5:844E (talk) 19:46, 3 November 2022 (UTC)
 * Oppose Too much ambiguity about the definition of "Teflon", current precise chemical name is fine. Hemiauchenia (talk) 20:35, 4 November 2022 (UTC)

Application for jewelry
The point about jewelry in the applications section states "PTFE is also used to make body jewellery as it's much safer to wear compared to materials like acrylic, that release toxics into the body at 26.6°C, unlike PTFE at 650–700°C." while the latter temperatures are likely meant in °C, as shown below in the first sentence of the safety section. Also there is no citation for that acrylic releases toxins at 26.6 °C. In addition there should be a space before the °C symbol, like "26.6 °C" instead of "26.6°C" and "toxins" instead of "toxics". Also the 26.6 might be in °F, since the PTFE decomposition temperature is wrong in the same way. 92.224.202.135 (talk) 21:26, 16 December 2022 (UTC)

Polytetrafluoroethylene
Speak Karthivikram (talk) 14:42, 27 December 2022 (UTC)

Thermal stability conflicting numbers
There are conflicting statements regarding the decomposition temperature of PTFE, see the 2 quotes below. Given that PTFE is regularly used above 200 °C, I doubt that the first number (200 °C decomposition) is correct. Hence I checked the source of that number and this is what it says:


 * There are several types of Teflon fluorocarbon resins in commercial use, each differing in thermal stability and therefore differing in the amounts of the several decomposition products evolved at various temperatures.
 * [...]
 * There is no hazard from pyrolysis products of Teflon fluorocarbon resins at temperatures of 200°C and below. Above 200°C, where pyrolysis of the resin is detectable, several fluorocarbon gases and a sublimate are evolved.

"Teflon fluorocarbon resins" is defined as:


 * *“Teflon” is the resistered trademark of the DuPont Company for its TFE and FEP fluorocarbon resins. This Guide pertains to “Teflon” TFE (polymer of tetrafluoroethylene) and FEP (polymer of fluorinated ethylene propylene) fluorocarbon resins.

Hence I will remove that, since it is not about PTFE but instead the less stable FEP and TFE.


 * == Processing ==
 * Processing PTFE can be difficult and expensive, because the high melting temperature, 327 °C (621 °F), is above the initial decomposition temperature, 200 °C (392 °F).


 * == Safety ==
 * While PTFE is stable at lower temperatures, it begins to deteriorate at temperatures of about 260 °C (500 °F), it decomposes above 350 °C (662 °F), and pyrolysis occurs at temperatures above 400 °C (752 °F).

Eheran (talk) 11:59, 2 May 2024 (UTC)