Methyl vinyl ether

Structural formula
General
Surname	Methyl vinyl ether
other names	Methoxyethene ( IUPAC ) Methyl vinyl oxide Methoxyethylene Vinyl methyl ether
Molecular formula	C 3 H 6 O
Brief description	colorless, extremely flammable gas with a sweet, penetrating odor
External identifiers / databases
CAS number 107-25-5 EC number 203-475-4 ECHA InfoCard 100.003.161 PubChem 7861 ChemSpider 7573 Wikidata Q904476
properties
Molar mass	58.08 g mol −1
Physical state	gaseous
density	0.77 g cm −3 (0 ° C)
Melting point	−122 ° C
boiling point	6 ° C
Vapor pressure	157 k Pa (20 ° C)
solubility	poor in water (9.7 g l −1 at 20 ° C) soluble in alcohol, ether, acetone, benzene
Refractive index	1.3730 (0 ° C)
safety instructions
GHS hazard labeling from  Regulation (EC) No. 1272/2008 (CLP) , expanded if necessary danger H and P phrases H: 220-231-280-412 P: 210-377-381-410 + 403-202
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C

Methyl vinyl ether is a chemical compound from the group of vinyl ethers . It is the simplest representative of this group of substances and is therefore sometimes referred to simply as vinyl ether itself.

Extraction and presentation

Technically, methyl vinyl ether is produced by reacting methanol with acetylene ( Reppe vinylation ) at temperatures of 80–150 ° C. and pressures of 5–30 bar in the presence of potassium methoxide in jet loop reactors .

The reaction is carried out in the liquid phase. The product is usually purified and worked up by distillation . The process gives very high yields and space-time yields , the conversion is 99% based on acetylene.

properties

Methyl vinyl ether polymerizes easily and then forms polymethyl vinyl ether (PMVE, CAS number: 9003-09-2) with the formula (CH ₃ OCH-CH ₂ ) _n .

Acetaldehyde is formed on contact with acids and acidic substances (e.g. calcium chloride ) .

Safety-related parameters

Methyl vinyl ether is extremely flammable ( flash point −60 ° C) and forms an explosive mixture with air. The explosion range is between 2.2% by volume (54 g / m³) as the lower explosion limit (LEL) and 28.2% by volume (694 g / m³) as the upper explosion limit (UEL). The ignition temperature is 220 ° C. The substance therefore falls into temperature class T3. It is chemically unstable and tends to polymerize spontaneously and exothermically .

use

Methyl vinyl ether is used as an adjuvant in the mass spectrometry of certain chemical compounds and as an intermediate in the production of other chemical compounds (e.g. glutaraldehyde ).

Risk assessment

In 2015, methyl vinyl ether was included in the EU's ongoing action plan ( CoRAP ) in accordance with Regulation (EC) No. 1907/2006 (REACH) as part of substance evaluation . The effects of the substance on human health and the environment are re-evaluated and, if necessary, follow-up measures are initiated. The reasons for the uptake of methyl vinyl ether were concerns about consumer use , exposure of sensitive population groups and exposure of workers as well as the possible risk from reproductive toxicity . The re-evaluation took place from 2018 and was carried out by Latvia . A final report was then published.

Individual evidence

1. ↑ ^{a b c d e f g h i j k} Entry on methyl vinyl ether in the GESTIS substance database of the IFA , accessed on January 10, 2017(JavaScript required) .
2. ↑ David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 89th edition. (Internet version: 2009), CRC Press / Taylor and Francis, Boca Raton, FL, Physical Constants of Organic Compounds, pp. 3-378.
3. ↑ David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Physical Constants of Organic Compounds, pp. 3-378.
4. ↑ Entry on methyl vinyl ether in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .
5. ↑ ^{a b} Patent EP1625107B1 : Continuous process for the production of methyl vinyl ether. Published on December 19, 2007 , applicant: BASF SE, inventors: Katrin Klass, Heike Becker, Regina Vogelsang, Alexander Hauk, Markus Siegert, Jochem Henkelmann. ‌
6. ↑ Christian Malosse, Lucien Kerhoas, Jacques Einhorn: Gas-phase reagents for carbon-carbon double bond location: new applications: II. Use of vinyl methyl ether chemical ionization mass spectrometry to characterize C23 to C33 insect cuticular alkenes . In: Journal of Chromatography A . tape 803 , no. 1-2 , 1998, pp. 203-209 , doi : 10.1016 / S0021-9673 (97) 01285-5 .
7. ↑ Eberhard Breitmaier, Günther Jung: Organic chemistry: Basics, substance classes, reactions, concepts, molecular structures . 5th edition. Georg Thieme Verlag, Stuttgart 2005, ISBN 978-3-13-541505-5 , p. 239 ( limited preview in Google Book search).
8. ↑ European Chemicals Agency (ECHA): Substance Evaluation Conclusion and Evaluation Report .
9. ↑ Community rolling action plan ( CoRAP ) of the European Chemicals Agency (ECHA): methyl vinyl ether , accessed on May 1, 2020.