Terephthaloyl chloride (TCL, 1,4-benzenedicarbonyl chloride) is the acyl chloride of terephthalic acid. It is a white solid at room temperature. It is one of two precursors used to make Kevlar, the other being p-phenylenediamine. TCL is used as a key component in performance polymers and aramid fibers, where it imparts flame resistance, chemical resistance, temperature stability, light weight, and very high strength. TCL is also an effective water scavenger, used to stabilize isocyanates and urethane prepolymers.
Preparation
Terephthalic acid dichloride is produced commercially by the reaction of 1,4-bis(trichloromethyl)benzene with terephthalic acid:[2]
- C6H4(CCl3)2 + C6H4(CO2H)2 → 2 C6H4(COCl)2 + 2 HCl
It can also be obtained by chlorination of dimethyl terephthalate.[3]
Use
TCL is used for making various copolymers and aramid polymers such as Heracron, Twaron and Kevlar:
References
- ^ a b Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book). Cambridge: The Royal Society of Chemistry. 2014. p. 797. doi:10.1039/9781849733069-FP001 (inactive 2024-06-29). ISBN 978-0-85404-182-4.
{{cite book}}: CS1 maint: DOI inactive as of June 2024 (link) - ^ Pfoertner, Karl-Heinz (2000). "Photochemistry". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a19_573. ISBN 978-3527306732.
- ^ EP patent 0095698, Walter Böckmann, Friedrich Brühne, Karl-August Lipper, "Verfahren zur Herstellung von Terephthalsäure- und Isophthalsäuredichlorid", published 1983-12-07, assigned to Bayer AG
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