Hexamethylenediamine

Hygroscopic semi-gloss papers with ammoniacal odor

Fixed

0.83 g · cm -3

41 ° C.

204 ° C

25 Pa ( 20 ° C)

Easily soluble in water ( 800 g · l-1 at 20 ° C ) and ethanol

Risk

750 mg · kg -1 ( LD50, rat, oral)

Template: Infobox chemical / molecular formula search available

Hexamethylenediamine ( HMD HMDA ) is a chemical compound selected from the group of aliphatic amines and an important intermediate for the production of polyamides.

Production

Hexamethylene diamine is prepared industrially by hydrogenation of adipodinitrile by two different methods. In the first method, has been developed by the DuPont Company, the hydrogenation in the presence of ammonia takes place at a high pressure around 250. The catalyst is a fixed bed of iron. In the second process, developed by Monsanto Company, is hydrogenated at an average pressure of 40. The hydrogenation is carried out without a solvent at low additive amounts of alkali metal hydroxides ( e.g. sodium hydroxide ) to Raney nickel catalyst in suspension.

In the laboratory, offers a production of furfural, furfural is decarbonylated in over a ZnO - Cr2O3 contact. With the furan obtained can now with HCl ether cleavage ( favored by the diene character ) can be performed. After a reaction with sodium cyanide and complete hydrogenation is also hexamethylenediamine.

Use

Hexamethylenediamine is an intermediate for polyamides such as nylon. This plastic (polymer) is formed as a condensation product of adipic acid and hexamethylene diamine with elimination of water, the monomeric intermediate is named after the first letter of the components also AH salt. By the reaction of hexamethylene diamine with phosgene, hexamethylene diisocyanate is obtained which is used as a component for preparing polyurethanes.