Epichlorohydrin

Structural formula
	Simplified structural formula without stereochemistry
General
Surname	Epichlorohydrin
other names	2- (chloromethyl) oxirane ( IUPAC ) ; 1-chloro-2,3-epoxypropane;
Molecular formula	C 3 H 5 ClO
Brief description	colorless, pungent smelling liquid
External identifiers / databases
EC number	203-439-8
ECHA InfoCard	100.003.128
PubChem	7835
ChemSpider	13837112
Wikidata	Q423083
properties
Molar mass	92.53 g mol −1
Physical state	liquid
density	1.18 g cm −3 (20 ° C)
Melting point	−48 ° C
boiling point	116 ° C
Vapor pressure	16.3 h Pa (20 ° C); 28.5 hPa (30 ° C); 47.9 hPa (40 ° C); 77.6 hPa (50 ° C);
solubility	moderate in water (60 g l −1 ); soluble in benzene , carbon tetrachloride , diethyl ether and ethanol ;
Refractive index	1.4358 (25 ° C)
safety instructions
H and P phrases	H: 226-301 + 311 + 331-314-317-350
	P: 201-261-280-301 + 310-305 + 351 + 338-310
MAK	Switzerland: 2 ml m −3 or 8 mg m −3
Thermodynamic properties
ΔH f 0	−148.4 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

Epichlorohydrin is a colorless , low- viscosity liquid that smells of chloroform . It was recognized in animal experiments as clearly carcinogenic, which is why no MAK value can be given. Most epichlorohydrin is synthesized as a racemate . Whenever epichlorohydrin is mentioned without further name components, the racemate [1: 1 mixture of ( R ) -epichlorohydrin and ( S ) -epichlorohydrin] is always meant. The pure enantiomers are also known, but are of little importance.

Extraction and presentation

The conventional production of epichlorohydrin 4 is performed by the reaction of allyl chloride 1 with hypochlorous acid to 1,3-dichloropropane-2-ol 2 and 2,3-dichloropropane-1-ol 3 and subsequent treatment with sodium hydroxide (NaOH) to epichlorohydrin 4 .

Another production possibility is based on the use of glycerine (e.g. from biodiesel production ), which is also converted into 1,3-dichloropropan-2-ol via hydrochloric acid and then converted into epichlorohydrin with NaOH . In these reactions, epichlorohydrin is obtained as a racemate .

properties

Chemical properties

Epichlorohydrin reacts quickly with nucleophilic compounds, e.g. B. amines , with opening of the epoxy ring. Under suitable reaction conditions, it reacts by splitting off chloride and forming a new epoxide . It is therefore used by industry to introduce the epoxy group into, for example, resins .

Safety-related parameters

Epichlorohydrin forms highly flammable vapor-air mixtures. The compound has a flash point of 28 ° C. The explosion range is between 2.3 vol.% (86 g / m ³ ) as the lower explosion limit (LEL) and 34.4 vol.% (1315 g / m ³ ) as the upper explosion limit (UEL). The lower explosion point is 26 ° C. The limit gap width was determined to be 0.74 mm. This results in an assignment to explosion group IIB. The ignition temperature is 385 ° C. The substance therefore falls into temperature class T2.

use

Epichlorohydrin is produced on an industrial scale. In the picture a tank container with epichlorohydrin on a freight wagon .

Until a few years ago, a large proportion of epichlorohydrin was used in the production of glycerine and glycidol , but the proportion of synthetic glycerine production fell sharply due to the large amounts of glycerine that result from biodiesel production.

Use of an epoxy resin as an insulating agent on a hybrid circuit

Above all as a component in the production of epoxy resins , which, in addition to their use as materials, are also used as wet strength agents in the production of paper (e.g. in the production of tea bag paper and kitchen paper ) and as two-component adhesives ( bisphenol A resins) Epichlorohydrin plays a big role. It is also part of synthetic elastomers and textile auxiliaries such as the polyamide- epichlorohydrin polymer Hercosett , which is used as a shrinkage inhibitor in textiles.

safety instructions

Epichlorohydrin is toxic and carcinogenic. It can diffuse through intact skin .

proof

The substance can be detected using test tubes , gas chromatography or a PID sensor .

literature

Ullmann 5th edition Volume A9 p. 539 f; Beilstein EIII 17.

Individual evidence

↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l ^m ⁿ ^o ^p ^q Entry on 1-chloro-2,3-epoxypropane in the GESTIS substance database of the IFA , accessed on October 11, 2019(JavaScript required) .
↑ Entry on α-epichlorohydrin. In: Römpp Online . Georg Thieme Verlag, accessed on September 29, 2014.
↑ 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. 3-228.
↑ Entry on 1-chloro-2,3-epoxypropane 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 .
↑ Swiss Accident Insurance Fund (Suva): Limits - Current MAK and BAT values (search for 106-89-8 or 1-chloro-2,3-epoxypropane (epichlorohydrin) ), 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. 5-23.
↑ Bruce M. Bell et al .: Glycerin as a Renewable Feedstock for Epichlorohydrin Production. The GTE Process. ( Memento of December 30, 2009 in the Internet Archive ) (PDF; 697 kB) Clean 36 (8), 2008; Pp. 657-661.
↑ ^a ^b ^c ^d ^e E. Brandes, W. Möller: Safety-related parameters. Volume 1: Flammable Liquids and Gases. Wirtschaftsverlag NW - Verlag für neue Wissenschaft, Bremerhaven 2003.

[GESTIS-1] ↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l ^m ⁿ ^o ^p ^q Entry on 1-chloro-2,3-epoxypropane in the GESTIS substance database of the IFA , accessed on October 11, 2019(JavaScript required) .

[2] Entry on α-epichlorohydrin. In: Römpp Online . Georg Thieme Verlag, accessed on September 29, 2014.

[CRC90_3_228-3] 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. 3-228.

[CLP_100.003.128-4] Entry on 1-chloro-2,3-epoxypropane 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] Swiss Accident Insurance Fund (Suva): Limits - Current MAK and BAT values (search for 106-89-8 or 1-chloro-2,3-epoxypropane (epichlorohydrin) ), accessed on November 2, 2015.

[CRC90_5_23-6] 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. 5-23.

[7] Bruce M. Bell et al .: Glycerin as a Renewable Feedstock for Epichlorohydrin Production. The GTE Process. ( Memento of December 30, 2009 in the Internet Archive ) (PDF; 697 kB) Clean 36 (8), 2008; Pp. 657-661.

[Brandes-8] E. Brandes, W. Möller: Safety-related parameters. Volume 1: Flammable Liquids and Gases. Wirtschaftsverlag NW - Verlag für neue Wissenschaft, Bremerhaven 2003.