Ethylene DiChloride (EDC)
The chemical compound 1,2-dichloroethane commonly known as ethylene dichloride (EDC), is a chlorinated hydrocarbon. It is a colorless liquid with a chloroform-like odor. The most common use of 1,2-dichloroethane is in the production of vinyl chloride, which is used to make polyvinyl chloride (PVC) pipes, furniture and automobile upholstery, wall coverings, housewares, and automobile parts. 1,2-Dichloroethane is also used generally as an intermediate for other organic chemical compounds and as a solvent. It forms azeotropes with many other solvents, including water (b.p. 70.5 °C) and other chlorocarbons.
Vinyl chloride monomer (VCM) production
Approximately 95% of the world’s production of 1,2-dichloroethane is used in the production of vinyl chloride monomer (VCM, chloroethene) with hydrogen chloride as a byproduct. VCM is the precursor to polyvinyl chloride.
Cl−CH2−CH2−Cl → H2C=CH−Cl + HCl
The hydrogen chloride can be re-used in the production of more 1,2-dichloroethane via the oxychlorination route described above.
As a good polar aprotic solvent, 1,2-dichloroethane could be used as degreaser and paint remover but is now banned from use due to its toxicity and possible carcinogenity. As a useful ‘building block’ reagent, it is used as an intermediate in the production of various organic compounds such as ethylenediamine. In the laboratory it is occasionally used as a source of chlorine, with elimination of ethene and chloride.
Via several steps, 1,2-dichloroethane is a precursor to 1,1,1-trichloroethane, which is used in dry cleaning. Historically, 1,2-dichloroethane was used as an anti-knock additive in leaded fuels to scavenge lead from cylinders and valves preventing buildup.