Tetrafluoroethylene

Structural formula
General
Surname	Tetrafluoroethylene
other names	1,1,2,2-tetrafluoroethylene ( IUPAC ) R-1114 TFE
Molecular formula	C 2 F 4
Brief description	extremely flammable, colorless gas with a sweet odor
External identifiers / databases
CAS number 116-14-3 EC number 204-126-9 ECHA InfoCard 100,003,752 PubChem 8301 Wikidata Q412460
properties
Molar mass	100.02 g mol −1
Physical state	gaseous
density	4.51 g l −1 (0 ° C)
Melting point	−142.5 ° C
boiling point	−75.6 ° C
Vapor pressure	2.95 M Pa (20 ° C)
solubility	heavy in water (179 mg l −1 )
safety instructions
GHS labeling of hazardous substances danger H and P phrases H: 220-280-350i-371 P: 210-410 + 403-260-281
Global warming potential	<1 (based on 100 years)
Thermodynamic properties
ΔH f 0	−658.9 kJ mol −1
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Tetrafluoroethylene (TFE) is a chemical compound from the group of fluoroalkenes and at the same time the simplest fully fluorinated compound .

Extraction and presentation

TFE can be produced by the fluorination of chloroform and subsequent pyrolysis of the chlorodifluoromethane produced.

${\displaystyle \mathrm {CHCl_{3}+2\ HF\longrightarrow CHClF_{2}+2\ HCl} }$

${\displaystyle \mathrm {2\ CHClF_{2}\longrightarrow C_{2}F_{4}+2\ HCl} }$

properties

TFE is not chemically stable; without oxygen it can break down to carbon and tetrafluoromethane , thereby releasing large amounts of energy. It is usually provided with a stabilizer , but the effect of this can be canceled when heated. Its critical temperature is 33.3 ° C, its critical pressure is 40.5 bar, its critical density is 0.58 g · cm ⁻³ , its triple point temperature is −131.25 ° C and its triple point pressure is 0.01168 bar .

use

Tetrafluoroethylene is used to produce polytetrafluoroethylene (PTFE) and as a copolymer of hexafluoropropylene and ethylene .

In refrigeration technology, it is the subject of current research as a refrigerant due to its low global warming potential and is a candidate for use in mixtures primarily with difluoromethane or R32, since decomposition reactions occurred in tests as a pure substance. It would be used as a replacement for pure R32 in refrigeration equipment from mainly Japanese manufacturers.

safety instructions

Tetrafluoroethylene is classified as carcinogenic category 2 (substances that are to be regarded as carcinogenic for humans).

Individual evidence

1. ↑ ^{a b c d e f g h i j} Entry on tetrafluoroethene in the GESTIS substance database of the IFA , accessed on February 17, 2017(JavaScript required) .
2. ↑ G. Myhre, D. Shindell et al .: Climate Change 2013: The Physical Science Basis . Working Group I contribution to the IPCC Fifth Assessment Report. Ed .: Intergovernmental Panel on Climate Change . 2013, Chapter 8: Anthropogenic and Natural Radiative Forcing, pp. 24-39; Table 8.SM.16 ( PDF ).
3. ↑ David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Standard Thermodynamic Properties of Chemical Substances, pp. 5-21.
4. ↑ Dae Jin Sung, Dong Ju Moon, Yong Jun Lee, Suk-In Hong: Catalytic Pyrolysis of Difluorochloromethane to Produce Tetrafluoroethylene. In: International Journal of Chemical Reactor Engineering. 2, 2004, doi : 10.2202 / 1542-6580.1065 .
5. ^ Hashimoto, M .: Development of New Low-GWP Refrigerants-Refrigerant Mixtures Including HFO-1123 . In: Science and Technology for the Built Environment . tape 25 . Taylor & Francis, 2019, pp. 776-783 .
6. ↑ National Institute of Environmental Health Sciences , 13th Report on Carcinogens (RoC): Tetrafluoroethylene , accessed November 18, 2014.