Dimethoxymethane

Structural formula
General
Surname	Dimethoxymethane
other names	Methylal; Formally; Formaldehyde dimethyl acetal; Methylene dimethyl ether; OME1;
Molecular formula	C 3 H 8 O 2
Brief description	colorless liquid with a characteristic odor
External identifiers / databases
EC number	203-714-2
ECHA InfoCard	100.003.378
PubChem	8020
Wikidata	Q411496
properties
Molar mass	76.1 g mol −1
Physical state	liquid
density	0.86 g cm −3 (20 ° C)
Melting point	−105 ° C
boiling point	42 ° C
Vapor pressure	426 hPa (20 ° C); 639 hPa (30 ° C); 934 hPa (40 ° C); 1340 hPa (50 ° C);
solubility	soluble in water (285 g l −1 at 20 ° C), ethanol, diethyl ether and hydrocarbons
Refractive index	1.3513 (20 ° C)
safety instructions
H and P phrases	H: 225-319
	EUH: 019
	P: 210-305 + 351 + 338
MAK	DFG : 1000 ml m −3 or 3200 mg m −3 ; Switzerland: 1000 ml m −3 or 3100 mg m −3 ;
Thermodynamic properties
ΔH f 0	−377.8 kJ / mol
	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

Dimethoxymethane , also known as methylal , is a clear, colorless, flammable liquid with a low boiling point, low viscosity and good solvent properties.

Extraction and presentation

Dimethoxymethane can be produced by the oxidation of methanol or the reaction of formaldehyde with methanol.

properties

Physical Properties

Dimethoxymethane is a colorless, volatile, highly flammable liquid that smells of chloroform . The compound boils at 42 ° C. under normal pressure . According to Antoine, the vapor pressure function results from log ₁₀ (P) = A− (B / (T + C)) (P in kPa, T in K) with A = 5.50613, B = 804.78 and C = −85 , 3 in the temperature range from 273 to 316 K or with A = 7.06105, B = 1623.024 and C = 5.834 in the temperature range from 273 to 318 K. The critical values are 480.6 K for the critical temperature, 39, 5 bar for the critical pressure and 4.69 mol·l ⁻¹ for the critical density. It can be mixed with most organic solvents. With a water content of 2.69 mol% and a pressure of 101.38 kPa, a mixture boiling homogeneously azeotropically at 41.9 ° C. is formed.

Chemical properties

In the presence of aqueous acids, the compound hydrolyzes to formaldehyde and methanol. Dimethoxymethane tends to form peroxides in the presence of air.

Safety-related parameters

The compound forms highly flammable vapor-air mixtures. It has a flash point of −30.5 ° C. The explosion range is between 2.2% by volume (71 g / m ³ ) as the lower explosion limit (LEL) and 19.9% by volume (630 g / m ³ ) as the upper explosion limit (UEL). The limit gap width was determined to be 0.86 mm. This results in an assignment to explosion group IIB. The ignition temperature is 235 ° C. The substance therefore falls into temperature class T3.

use

Dimethoxymethane is mainly used as a solvent and in the production of perfumes, resins, paint removers and protective coatings. It is also being tested as a fuel additive and as a synthetic fuel.

Individual evidence

↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l ^m ⁿ ^o ^p ^q ^r Entry on dimethoxymethane in the GESTIS substance database of the IFA , accessed on May 27, 2019(JavaScript required) .
↑ ^a ^b entry on dimethoxymethane. In: Römpp Online . Georg Thieme Verlag, accessed on May 26, 2019.
↑ 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. 3-188.
↑ Swiss Accident Insurance Fund (Suva): Limit values - current MAK and BAT values (search for 109-87-5 or dimethoxymethane ), accessed on November 2, 2015.
↑ 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. 5-25.
↑ Patent US6379507B1 Process for producing methylal , Asahi Kasei Kabushiki Kaisha, April 30, 2002 Link .
↑ Xuemei Zhang, Sufei Zhang, Chungui Jian: Synthesis of methylal by catalytic distillation in Chem. Eng. Res. Design 89 (2011) 573-580, doi : 10.1016 / j.cherd.2010.09.002 .
↑ Ewell, RH; Welch, LM: Maximum Boiling Mixtures of chloroparaffins with Donor Liquids in J. Am. Chem. Soc. 63 (1941) 2475-2478, doi : 10.1021 / ja01854a045 .
Jump up ↑ Richard M. Stephenson, Stanislaw Malanowski: Handbook of the Thermodynamics of Organic Compounds , Elsevier 1987, ISBN 978-94-010-7923-5 , doi : 10.1007 / 978-94-009-3173-2 , p. 84.
↑ Kobe, KA; Mathews, JF: Critical Properties and Vapor Pressures of Some Organic Nitrogen and Oxygen Compounds in J. Chem. Eng. Data 15 (1970) 182-186, doi : 10.1021 / je60044a012 .
↑ David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 92nd edition. (Internet version: 2011), CRC Press / Taylor and Francis, Boca Raton, FL, Azeotropic Data for Binary Mixtures, pp. 6-210-6-228.
↑ PG Urben; MJ Pitt: Bretherick's Handbook of Reactive Chemical Hazards . 8th edition, Vol. 1, Butterworth / Heinemann 2017, ISBN 978-0-08-100971-0 , p. 295.
^ E. Brandes, W. Möller: Safety-related parameters - Volume 1: Flammable liquids and gases , Wirtschaftsverlag NW - Verlag für neue Wissenschaft GmbH, Bremerhaven 2003.
↑ Martin Härtl, Philipp Seidenspinner, Georg Wachtmeister, Eberhard Jacob: Synthetic Diesel Fuel OME1 - Solution Approach for the Conflict of Objectives NOx / Particle Emissions . In: Springer Verlag (ed.): MTZ - Motortechnische Zeitschrift . tape 75 , no. 7 , p. 68-73 .

[GESTIS-1] ↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l ^m ⁿ ^o ^p ^q ^r Entry on dimethoxymethane in the GESTIS substance database of the IFA , accessed on May 27, 2019(JavaScript required) .

[Roempp-2] try on dimethoxymethane. In: Römpp Online . Georg Thieme Verlag, accessed on May 26, 2019.

[CRC90_3_188-3] 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. 3-188.

[4] Swiss Accident Insurance Fund (Suva): Limit values - current MAK and BAT values (search for 109-87-5 or dimethoxymethane ), accessed on November 2, 2015.

[CRC90_5_25-5] 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. 5-25.

[6] Patent US6379507B1 Process for producing methylal , Asahi Kasei Kabushiki Kaisha, April 30, 2002 Link .

[Zhang-7] Xuemei Zhang, Sufei Zhang, Chungui Jian: Synthesis of methylal by catalytic distillation in Chem. Eng. Res. Design 89 (2011) 573-580, doi : 10.1016 / j.cherd.2010.09.002 .

[Ewell-8] Ewell, RH; Welch, LM: Maximum Boiling Mixtures of chloroparaffins with Donor Liquids in J. Am. Chem. Soc. 63 (1941) 2475-2478, doi : 10.1021 / ja01854a045 .

[Stephenson_Malanowski-9] Jump up ↑ Richard M. Stephenson, Stanislaw Malanowski: Handbook of the Thermodynamics of Organic Compounds , Elsevier 1987, ISBN 978-94-010-7923-5 , doi : 10.1007 / 978-94-009-3173-2 , p. 84.

[Kobe-10] Kobe, KA; Mathews, JF: Critical Properties and Vapor Pressures of Some Organic Nitrogen and Oxygen Compounds in J. Chem. Eng. Data 15 (1970) 182-186, doi : 10.1021 / je60044a012 .

[CRC_Handbook-11] David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 92nd edition. (Internet version: 2011), CRC Press / Taylor and Francis, Boca Raton, FL, Azeotropic Data for Binary Mixtures, pp. 6-210-6-228.

[Bretherick-12] PG Urben; MJ Pitt: Bretherick's Handbook of Reactive Chemical Hazards . 8th edition, Vol. 1, Butterworth / Heinemann 2017, ISBN 978-0-08-100971-0 , p. 295.

[Brandes-13] E. Brandes, W. Möller: Safety-related parameters - Volume 1: Flammable liquids and gases , Wirtschaftsverlag NW - Verlag für neue Wissenschaft GmbH, Bremerhaven 2003.

[14] Martin Härtl, Philipp Seidenspinner, Georg Wachtmeister, Eberhard Jacob: Synthetic Diesel Fuel OME1 - Solution Approach for the Conflict of Objectives NOx / Particle Emissions . In: Springer Verlag (ed.): MTZ - Motortechnische Zeitschrift . tape 75 , no. 7 , p. 68-73 .