Ethylene thiourea

• Imidazolidine -2-thione
• 2- imidazolidinethione
• 2- Thioxoimidazolidin
• 4,5- dihydroimidazole -2-thione

Colorless, crystalline solid with a faint, aromatic odor

Fixed

1.4 g · cm -3 ( 20 ° C)

203-204 ° C

0.2 hPa (170 ° C)

• Poorly in cold water ( 19 g · l-1 at 20 ° C)
• In hot water, methanol and ethanol, slightly soluble, insoluble in benzene, diethyl ether and acetone

Risk

1832 mg · kg -1 ( LD50, rat, oral)

Template: Infobox chemical / molecular formula search available

Ethylene thiourea, abbreviated ETU (of English. Ethylenethiourea ), is a commercially available rubber accelerators and beyond a toxicologically significant metabolite of the fungicide from the group of Ethylenbisdithiocarbamate (eg, zineb, maneb, Metiram ). The connection can also occur as a contaminant of these pesticides.

Production

The production of ethylene thiourea is carried out by reaction of ethylenediamine ( H2N -CH2-CH2 - NH2) with carbon disulfide (CS2 ) for dithiocarbamate and subsequent condensation reaction with the ring and elimination of hydrogen sulfide (H2S).

Application

The only important application is the use as a vulcanization accelerator for chloroprene rubber ( polychloroprene). In this function, according to the classical view ethylenethiourea assumes in the presence of metal oxides such as zinc oxide and magnesium oxide, the role of a sulfur donor ( sulfur donor). However, it was also demonstrated that binds ETU during the vulcanization of the nitrogen atoms to the polychloroprene. In the commercial ethylene thiourea is preferably free of dust either granulated or coated with oil to be found in a mixture with polymers ( angebatcht ), eg Rhenocure ® NPV / C.

Toxicology

In plant foods can occur ethylene thiourea as a residue from the decomposition of fungicides from the class of Ethylenbisdithiocarbamate ( EBDC ). Because of the toxicity and suspected carcinogenic effect is reported accordingly low ( BGBI Maximum Residue Level Regulation of 13 January 2003 ) for ETU the limit of 0.05 ppm. The analytical detection as recommended by the Federal Institute for Risk Assessment ( BfR) from 2002 is performed by gas chromatography with sulfur- specific flame photometric detector. A detection by a mass spectrometer, is also possible.