Полихлортрифлюороэтилен
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| Имена | |
|---|---|
| Другие имена
Поли (1-хлор-1,2,2-трифторэтилен)
Поли (этилен трифторид хлорид) Полимонохлортрифлюороэтилен Поли (трифторэтиленхлорид) Поли (хлоротрифлуороэтилен) Поли (трифторхлорэтен) Поли (хлоротрифторуэтен) Поли (трифторвинилхлорид) Поли (виниловый трифторхлорид) Kel-F 300; Kel-F 81 | |
| Identifiers | |
| Abbreviations | PCTFE, PTFCE[1] |
| ChemSpider |
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| ECHA InfoCard | 100.120.473 |
| MeSH | Polychlorotrifluoroethene |
CompTox Dashboard (EPA)
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| Properties | |
| (C2ClF3)n°° | |
| Molar mass | Variable |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Полихлортрифторэтилен ( PCTFE или PTFCE ) представляет собой термопластичный хлоро фторолимер с молекулярной формулой (CF 2 CCLF) N , где n - количество мономерных единиц в молекуле полимера . Он похож на политетрафторуэтена (PTFE), за исключением того, что он является гомополимером мономера хлоротрифлюороэтилена (CTFE) вместо тетрафторэтена. Он имеет самую низкую скорость передачи водяного пара любого пластика. [ 2 ]
История
[ редактировать ]Он был обнаружен в 1934 году [ 3 ] [ 4 ] Фриц Шлоффер и Отто Шерер, которые работали в компании IG Farben , Германия. [ 5 ]
Торговые названия
[ редактировать ]После Второй мировой войны PCTFE была коммерциализирована под торговым названием Kel-F 81 компанией MW Kellogg в начале 1950-х годов. [ 6 ] Название «Kel-F» было получено из «kellogg» и «фторолимера», который также представляет другие фторолимеры, такие как поли (хлоротрифторэтилен-ко-винилиден фторид) (Kel-F 800). [7] These were acquired by 3M Company in 1957.[6] Но 3M прекратил производство Kel-F к 1996 году.
PCTFE resin is now manufactured in different trade names such as Neoflon PCTFE from Daikin, Voltalef from Arkema or Aclon from Allied Signal. PCTFE films are sold under the tradename Aclar by Allied Signal.[8] Tradenames of PCTFE in other manufacturing companies include Hostaflon C2 from Hoechst, Fluon from ICI, Aclar from Honeywell, Plaskon from Allied Chemical Corporation, Halon from Ausimont USA,[9][10] and Ftoroplast-3 in USSR and Russian Federation.[11]
Synthesis
[edit]PCTFE is an addition homopolymer. It is prepared by the free-radical polymerization of chlorotrifluoroethylene (CTFE)[12] and can be carried out by solution, bulk, suspension and emulsion polymerization.[13]
Properties
[edit]PCTFE has high tensile strength and good thermal characteristics. It is nonflammable[14] and the heat resistance is up to 175 °C.[15] It has a low coefficient of thermal expansion. The glass transition temperature (Tg) is around 45 °C.[1]
PCTFE has one of the highest limiting oxygen index (LOI).[16] It has good chemical resistance. It also exhibits properties like zero moisture absorption and non wetting.[15][17]
It does not absorb visible light. When subjected to high-energy radiation, it undergoes degradation like PTFE.[18] It can be used as a transparent film.[14]
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,[19] around 210–215 °C.[2]
PCTFE is resistant to the attack by most chemicals and oxidizing agents, a property exhibited due to the presence of high fluorine content. However, it swells slightly in halocarbon compounds, ethers, esters and aromatic compounds.[2] PCTFE is resistant to oxidation because it does not have any hydrogen atoms.[20]
PCTFE exhibits a permanent dipole moment due to the asymmetry of its repeating unit. This dipole moment is perpendicular to the carbon-chain axis.[21]
Differences from PTFE
[edit]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.[22] PCTFE has lower viscosity, higher tensile strength and creep resistance than PTFE.[1]
PCTFE is injection-moldable and extrudable, whereas PTFE is not.[1]
Applications
[edit]PCTFE finds majority of its application due to two main properties: water repulsion and chemical stability. PCTFE films are used as a protective layer against moisture. These include:
- moisture barrier in pharmaceutical blister packaging,
- water-vapour barrier for protecting phosphor coatings in electroluminescent lamps (the phosphor chemicals are sensitive to moisture),
- protection of liquid-crystal display (LCD) panels, which are sensitive to moisture,
- cryogenic seals and composants.[23]
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 transparent eyeglasses, tubes, valves, chemical tank liners, O-rings, seals and gaskets.[15]
PCTFE is used to protect sensitive electronic components because of its excellent electrical resistance and water repulsion. Other uses include flexible printed circuits and insulation of wires and cables.[24][22]
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.[2]
The cryogenic and liquid gas sector uses mainly PCTFE seals for their sealing solution as this material has low gas absorption and resist to temperature below 200 °C.
References
[edit]- ^ Jump up to: a b c d Christopher C. Ibeh (2011). THERMOPLASTIC MATERIALS Properties, Manufacturing Methods, and Applications. CRC Press. p. 491. ISBN 978-1-4200-9383-4.
- ^ Jump up to: a b c d C. H. Kurita (20 Jan 1988). "Appendix A" (PDF). D-ZERO COLD VALUE. pp. 58–61. Archived from the original (PDF) on 21 October 2013. Retrieved June 14, 2012.
- ^ Tsuyoshi Nakajima; Henri Groult (4 August 2005). Fluorinated Materials For Energy Conversion. Elsevier. p. 472. ISBN 978-0-08-044472-7. Retrieved 14 July 2012.
- ^ B. Améduri; Bernard Boutevin (7 July 2004). Well-architectured Fluoropolymers: Synthesis, Properties And Applications. Elsevier. p. 5. ISBN 978-0-08-044388-1. Retrieved 14 July 2012.
- ^ Koch 2012, p. 11.
- ^ Jump up to: a b Takashi Okazoe. "Synthetic Studies on Perfluorinated Compounds by Direct Fluorination" (PDF). p. 17. Retrieved July 14, 2012.
- ^ Suhithi M. Peiris; Gasper J. Piermarini (10 December 2008). Static Compression of Energetic Materials. Springer. pp. 158–. ISBN 978-3-540-68146-5. Retrieved 14 July 2012.
- ^ Sina Ebnesajjad (31 December 2000). Fluoroplastics, Volume 1: Non-Melt Processible Fluoroplastics. William Andrew. p. 74. ISBN 978-0-8155-1727-6. Retrieved 8 July 2012.
- ^ DIANE Publishing Company (1 July 1993). New Materials Society, Challenges and Opportunities: New Materials Science and Technology. DIANE Publishing. p. 8.42. ISBN 978-0-7881-0147-2. Retrieved 8 July 2012.
- ^ Ernst-Christian Koch (17 April 2012). Metal-Fluorocarbon Based Energetic Materials. John Wiley & Sons. p. 23. ISBN 978-3-527-32920-5. Retrieved 8 July 2012.
- ^ ГОСТ 13744-83 State Standard of USSR
- ^ Sina Ebnesajjad (31 December 2002). Melt Processible Fluoropolymers: The Definitive User's Guide and Databook. William Andrew. p. 636. ISBN 978-1-884207-96-9. Retrieved 8 July 2012.
- ^ Ebnesajjad 2000, p. 61.
- ^ Jump up to: a b Ruth Winter (2 August 2007). 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. iUniverse. p. 255. ISBN 978-0-595-44948-4. Retrieved 14 July 2012.
- ^ Jump up to: а беременный в Франсуа Кардарелли (2008). Справочник по материалам: краткая ссылка на рабочем столе . Спрингер. С. 708–709. ISBN 9781846286681 . ISBN 1846286689 .
- ^ Эбнесаджад, Сина. Флуоропластики, том 2: Распламениваемые фторполимеры - окончательное руководство пользователя и книга данных . п. 560.
- ^ «Пластмассы рассылания» . Получено 5 июня 2012 года .
- ^ JA Brydson (8 ноября 1999 г.). Пластмассы материалы . Баттерворт-Хейнеманн. С. 423–. ISBN 978-0-7506-4132-6 Полем Получено 30 июня 2012 года .
- ^ 2006 p
- ^ «Глава вторая: шестая часть» . Архивировано с оригинала 2012-01-07 . Получено 2012-06-13 .
- ^ «Диэлектрические свойства полукристаллического полихлорорторифлуороэтилена» (PDF) . Журнал исследований Национального бюро стандартов Раздел а . 66a (4): 1. 1962 . Получено 26 июня 2012 года .
- ^ Jump up to: а беременный Доминик В. Розато; Дональд В. Розато; Мэтью В. Розато (2004). Пластиковый материал продукта и справочник по выбору процессов . Elsevier. п. 75. ISBN 185617431x . ISBN 9781856174312 .
- ^ «Технические пластмассы для криогеники» . Общество благородных пластиков . Получено 2020-02-14 .
- ^ Mały 2006 , с. 37-39.