Editing Polychlorotrifluoroethylene

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| OtherNames = Poly(1-chloro-1,2,2-trifluoroethylene)<Br/>Poly(ethylene trifluoride chloride)<Br/>Polymonochlorotrifluoroethylene<Br/>Poly(trifluoroethylene chloride)<Br/>Poly(chlorotrifluoroethylene)<Br/>Poly(trifluorochloroethene)<Br/>Poly(chlorotrifluoroethene)<Br/>Poly(trifluorovinyl chloride)<Br/>Poly(vinyl trifluorochloride)<Br/>Kel-F 300; Kel-F 81
|Section1={{Chembox Identifiers
| Abbreviations = PCTFE, PTFCE<ref name="Ibeh">{{cite book | title=THERMOPLASTIC MATERIALS Properties, Manufacturing Methods, and Applications | publisher=CRC Press | author=Christopher C. Ibeh | year=2011 | pages=491 | isbn=978-1-4200-9383-4}}</ref>
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| MeSHName = Polychlorotrifluoroethene
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|Section2={{Chembox Properties
| Formula = (C<sub>2</sub>ClF<sub>3</sub>)<sub>''n''</sub>°°
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'''Polychlorotrifluoroethylene''' ('''PCTFE''' or '''PTFCE''') is a [[thermoplastic]] chloro[[fluoropolymer]] with the [[molecular formula]] {{chem name|(CF<sub>2</sub>CClF)<sub>''n''</sub>}}, where ''n'' is the number of [[monomer]] units in the [[polymer]] molecule. It is similar to [[polytetrafluoroethene]] (PTFE), except that it is a [[homopolymer]] of the monomer [[chlorotrifluoroethylene]] (CTFE) instead of tetrafluoroethene. It has the lowest [[water vapor transmission rate]] of any plastic.<ref name="cold wave">{{cite book | chapter-url=http://lss.fnal.gov/archive/d0-en/fermilab-d0-en-139.pdf | title=D-ZERO COLD VALUE | date=20 Jan 1988 | accessdate=June 14, 2012 | author=C. H. Kurita | pages=58–61 | chapter=Appendix A | archive-url=https://web.archive.org/web/20131021031019/http://lss.fnal.gov/archive/d0-en/fermilab-d0-en-139.pdf | archive-date=21 October 2013 | url-status=dead }}</ref>

== History ==
It was discovered in 1934<ref name="NakajimaGroult2005">{{cite book|author1=Tsuyoshi Nakajima|author2=Henri Groult|title=Fluorinated Materials For Energy Conversion|url=https://books.google.com/books?id=CYnwFyC1kv8C&pg=PA472|accessdate=14 July 2012|date=4 August 2005|publisher=Elsevier|isbn=978-0-08-044472-7|page=472}}</ref><ref name="AméduriBoutevin2004">{{cite book|author1=B. Améduri|author2=Bernard Boutevin|title=Well-architectured Fluoropolymers: Synthesis, Properties And Applications|url=https://books.google.com/books?id=K_CdPycY66sC&pg=PR5|accessdate=14 July 2012|date=7 July 2004|publisher=Elsevier|isbn=978-0-08-044388-1|page=5}}</ref> by Fritz Schloffer and Otto Scherer who worked at [[IG Farben]] Company, Germany.{{sfn|Koch|2012|p=11}}

== Trade names ==
After World War II, PCTFE was [[commercialized]] under the [[trade name]] of Kel-F 81 by [[M. W. Kellogg Company]] in early 1950s.<ref name="Okazoe"/> The name "Kel-F" was derived from "Kellogg" and "fluoropolymer", which also represents other fluoropolymers like the copolymer poly(chlorotrifluoroethylene-co-vinylidene fluoride) (Kel-F 800).<ref name="PeirisPiermarini2008">{{cite book|author1=Suhithi M. Peiris|author2=Gasper J. Piermarini|title=Static Compression of Energetic Materials|url=https://books.google.com/books?id=VVvlVvdbIJAC&pg=PA158|accessdate=14 July 2012|date=10 December 2008|publisher=Springer|isbn=978-3-540-68146-5|pages=158–}}</ref> These were acquired by [[3M Company]] in 1957.<ref name="Okazoe">{{cite web | url=http://repository.kulib.kyoto-u.ac.jp/dspace/bitstream/2433/70019/1/D_Okazoe_Takashi.pdf | title=Synthetic Studies on Perfluorinated Compounds by Direct Fluorination | accessdate=July 14, 2012 | author=Takashi Okazoe | pages=17}}</ref> 3M discontinued manufacturing of Kel-F by 1996.

PCTFE resin is now manufactured under different trade names such as Neoflon PCTFE from [[Daikin]], Voltalef from [[Arkema]], and Aclon from [[Honeywell]]. PCTFE films are sold under the tradename Aclar by Honeywell.<ref name="Ebnesajjad2000">{{cite book|author=Sina Ebnesajjad|title=Fluoroplastics, Volume 1: Non-Melt Processible Fluoroplastics|url=https://books.google.com/books?id=-H4yIE71aGMC&pg=PA74|accessdate=8 July 2012|date=31 December 2000|publisher=William Andrew|isbn=978-0-8155-1727-6|page=74}}</ref> Other current and former trade names of PCTFE include Hostaflon C2 from [[Hoechst AG|Hoechst]], Fluon from [[Imperial Chemical Industries|ICI]], Plaskon from [[Allied Chemical Corporation]], Halon from Ausimont USA,<ref name="Company1993">{{cite book|author=DIANE Publishing Company|title=New Materials Society, Challenges and Opportunities: New Materials Science and Technology|url=https://books.google.com/books?id=h9su3LgNVygC&pg=SA8-PA40|accessdate=8 July 2012|date=1 July 1993|publisher=DIANE Publishing|isbn=978-0-7881-0147-2|pages=8.42}}</ref><ref name="Koch2012">{{cite book|author=Ernst-Christian Koch|title=Metal-Fluorocarbon Based Energetic Materials|url=https://books.google.com/books?id=-W8ZoXTBmVkC&pg=PA22|accessdate=8 July 2012|date=17 April 2012|publisher=John Wiley & Sons|isbn=978-3-527-32920-5|page=23}}</ref> and Ftoroplast-3 in the USSR and Russian Federation.<ref>ГОСТ 13744-83 State Standard of USSR</ref>

== Synthesis ==
PCTFE is an addition homopolymer. It is prepared by the [[free-radical polymerization]] of [[chlorotrifluoroethylene]] (CTFE)<ref name="Ebnesajjad2002">{{cite book|author=Sina Ebnesajjad|title=Melt Processible Fluoropolymers: The Definitive User's Guide and Databook|url=https://books.google.com/books?id=x5N40jiWljYC&pg=PA636|accessdate=8 July 2012|date=31 December 2002|publisher=William Andrew|isbn=978-1-884207-96-9|page=636}}</ref> and can be carried out by [[solution polymerization|solution]], [[bulk polymerization|bulk]], [[suspension polymerization|suspension]] and [[emulsion polymerization]].{{sfn|Ebnesajjad|2000|p=61}}

== Properties ==
PCTFE has high [[tensile strength]] and good [[thermal characteristics]]. It is nonflammable<ref name="Winter2007">{{cite book|author=Ruth Winter|author-link=Ruth Winter (journalist)|title=A Consumer's Dictionary of Household, Yard and Office Chemicals: Complete Information About Harmful and Desirable Chemicals Found in Everyday Home Products, Yard Poisons, and Office Polluters|url=https://books.google.com/books?id=AREKhE-s8ycC&pg=PA255|accessdate=14 July 2012|date=2 August 2007|publisher=iUniverse|isbn=978-0-595-44948-4|page=255}}</ref> and the heat resistance is up to 175&nbsp;°C.<ref name="mHand"/> It has a low [[coefficient of thermal expansion]]. The [[glass transition temperature]] (''T''<sub>g</sub>) is around 45&nbsp;°C.<ref name="Ibeh" />

PCTFE has one of the highest [[limiting oxygen index]] (LOI).<ref>{{Cite book
| title = Fluoroplastics, Volume 2: Melt Processible Fluoropolymers – The Definitive User Guide and Data Book
| last = Ebnesajjad
| first = Sina
| pages = 560
}}</ref> It has good [[chemical resistance]]. It also exhibits properties like zero [[moisture]] absorption and non [[wetting]].<ref name="mHand">{{cite book | title=Materials Handbook: A Concise Desktop Reference | publisher=Springer | author=François Cardarelli | year=2008 | pages=708–709 | isbn=9781846286681 | url=https://books.google.com/books?id=PvU-qbQJq7IC&q=Polychlorotrifluoroethylene&pg=PA708}} {{ISBN|1846286689}}.</ref><ref name="kelf">{{cite web | url=http://www.ridoutplastics.com/kelf.html | title=RIDOUT PLASTICS | accessdate=June 5, 2012}}</ref>

It does not absorb [[visible light]]. When subjected to high-energy [[radiation]], it undergoes degradation like PTFE.<ref name="Brydson1999">{{cite book|author=J. A. Brydson|title=Plastics Materials|url=https://books.google.com/books?id=rka3nPiiRi4C&pg=PA423|accessdate=30 June 2012|date=8 November 1999|publisher=Butterworth-Heinemann|isbn=978-0-7506-4132-6|pages=423–}}</ref> It can be used as a transparent film.<ref name="Winter2007"/>

The presence of a [[chlorine]] atom, having greater atomic radius than that of [[fluorine]], hinders the close packing possible in PTFE. This results in having a relatively lower [[melting point]] among fluoropolymers,{{sfn|Drobny|2006|p=8, 22}} around 210–215&nbsp;°C.<ref name="cold wave" />

PCTFE is resistant to the attack by most chemicals and [[oxidizing agent]]s, a property exhibited due to the presence of high fluorine content. However, it swells slightly in [[Halocarbon|halocarbon compounds]], [[ethers]], [[esters]] and [[aromatic compounds]].<ref name="cold wave"/> PCTFE is resistant to oxidation because it does not have any [[hydrogen]] atoms.<ref>{{cite web |url=http://web.mst.edu/~wlf/chem381/chap26.html |title=Chapter Two: Sixth Part |accessdate=2012-06-13 |url-status=dead |archiveurl=https://web.archive.org/web/20120107120110/http://web.mst.edu/~wlf/chem381/chap26.html |archivedate=2012-01-07 }}</ref>

PCTFE exhibits a permanent [[Bond dipole moment|dipole moment]] due to the [[asymmetry]] of its repeating unit. This dipole moment is perpendicular to the carbon-chain axis.<ref>{{cite journal | url=http://nvlpubs.nist.gov/nistpubs/jres/066/4/V66.N04.A01.pdf | title=Dielectric Properties of Semicrystalline Polychlorotrifluoroethylene | journal=Journal of Research of the National Bureau of Standards Section A | accessdate=June 26, 2012 | year=1962 | pages=1 | volume=66A | issue = 4}}</ref>

== Differences from PTFE ==
{{See also|Polytetrafluoroethylene|label 1=PTFE}}
PCTFE is a homopolymer of [[chlorotrifluoroethylene]] (CTFE), whereas PTFE is a homopolymer of [[tetrafluoroethylene]]. The monomers of the former differs from that of latter structurally by having a [[chlorine]] atom replacing one of the [[fluorine]] atoms. Hence each [[repeating unit]] of PCTFE have a chlorine atom in place of a fluorine atom. This accounts for PCTFE to have less flexibility of chain and hence higher [[glass transition temperature]]. PTFE has a higher melting point and is more crystalline than PCTFE, but the latter is stronger and stiffer. Though PCTFE has excellent chemical resistance, it is still less than that of PTFE.<ref name="Plastic2004">{{cite book | url=https://books.google.com/books?id=IC937z02PJEC&q=PCTFE+major+uses+in+detail&pg=PA75 | title=Plastic Product Material and Process Selection Handbook | publisher=Elsevier |author1=Dominick V. Rosato |author2=Donald V. Rosato |author3=Matthew V. Rosato | year=2004 | pages=75 | isbn=185617431X}} {{ISBN|9781856174312}}.</ref> PCTFE has lower [[viscosity]], higher [[tensile strength]] and [[Creep (deformation)#Polymers|creep resistance]] than PTFE.<ref name="Ibeh" />

PCTFE is [[injection molding|injection-moldable]] and extrudable, whereas PTFE is not.<ref name="Ibeh" />

== Applications ==
PCTFE is used primarily for two properties: water repulsion and chemical stability. 

PCTFE films are used as protective layers against moisture. These include:
* [[moisture barrier]]s in [[Pharmaceutical packaging|pharmaceutical blister packaging]]
* water-vapour barriers for protecting [[phosphor]] coatings in [[electroluminescent lamp]]s (the phosphor chemicals are sensitive to moisture)
* protection of [[liquid-crystal display]] (LCD) panels, which are sensitive to moisture

Due to its chemical stability, it acts as a protective barrier against chemicals. It is used as a coating and prefabricated liner for chemical applications. PCTFE is also used for [[laminating]] other polymers like [[PVC]], [[polypropylene]], [[PETG]], [[APET]] etc.  It is also used in tubes, [[valves]], [[chemical tank]] liners, [[O-rings]], seals and [[gasket]]s.<ref name="mHand" />

PCTFE is used to protect sensitive [[electronic component]]s because of its excellent [[electrical resistance]] and water repulsion. Other uses include flexible [[printed circuit board|printed circuits]] and insulation of wires and cables.{{sfn|Drobny|2006|p=37-39}}<ref name="Plastic2004" />

Low-molecular-weight PCTFE waxes, oils and greases find their application as inert [[sealants]] and [[lubricants]]. They are also used as [[gyroscope]] flotation fluids and [[plasticizers]] for [[thermoplastics]].<ref name="cold wave"/>

PCTFE is used for cryogenic seals and components. The cryogenic and liquid gas sector uses mainly PCTFE seals as this material has low gas absorption and good resistance to temperatures below -200&nbsp;°C.<ref>{{Cite web|url=http://www.plastiques-nobles.com/en/technical-plastics-cryogenics/ |archive-url= https://web.archive.org/web/20240721170623/http://www.plastiques-nobles.com/en/technical-plastics-cryogenics/ |title=Technical plastics for cryogenics|website=Société des Plastiques Nobles|access-date=2020-02-14 |archive-date=2024-07-21 |url-status=dead}}</ref>

== References ==
{{Reflist}}

[[Category:Fluoropolymers]]
[[Category:Thermoplastics]]