Dimethylacetamide

  • N, N -dimethylacetamide
  • DMAC

Colorless to yellowish, hygroscopic liquid with a faint amine-like odor

Liquid

0.94 g · cm -3

-20 ° C

165 ° C

3.3 mbar ( 20 ° C)

Miscible with water and many organic solvents

1.4341 (25 ° C)

Risk

10 ml · m -3 ( or 36 mg · m -3)

4930 mg · kg -1 ( LD50, rat, oral)

Template: Infobox chemical / molecular formula search available

Dimethylacetamide (DMAc), more precisely N, N- dimethylacetamide, acetic acid is an amide. DMAc is used as the polar organic solvent.

Production

The large scale production of DMAC is effected by the reaction of acetic acid with dimethylamine and subsequent dehydration of the reaction mixture:

The product worked up and purified by distillation.

Properties

N, N -dimethylacetamide is a hygroscopic, colorless to yellow liquid with a faint odor, which is miscible with water. The compound is stable to boiling point in the absence of catalytically active substances such as water, acids, bases and alcohols to light and air. It decomposes in the heat of formation of nitrogen oxides, carbon monoxide and carbon dioxide produced. Its aqueous solution is acidic. The vapor pressure curve can be with the Antoine equation as log10 (p) = A- ( B / ( T C )) ( p in bar, T in K) with A = 4.88722, B = 1889.1 and C = -52.15 describe. When critical data is the critical temperature Tc = 384.85 ° C, the critical pressure pc = 40.3 bar and an acentric factor? C = 0.36351 known.

The compound is flammable vapor -air mixtures at elevated temperature. The compound has a flash point of 66 ° C. The explosion range is between 1.8 vol% (64 g/m3) as the lower explosive limit ( LEL) and 11.5 % by volume (415 g/m3 ) and upper explosive limit (UEL ). The ignition temperature is 490 ° C. The fabric falls within the temperature class T1.

Use

  • DMAC is a solvent for the production of acrylic fibers and polyurethane-based spandex fibers.
  • DMAC is used as a solvent for polyimide coatings and films.
  • DMAC can be used both as a solvent and as a reactant in the production of many fine chemicals.
  • Mixtures of DMAC with lithium chloride used as a solvent for cellulose fibers.

Safety

DMAC is harmful by inhalation and in contact with skin. It irritates the eyes and affects most likely teratogenic effect on the fetus. DMAC is not carcinogenic or mutagenic in studies using microorganisms or mammalian cell cultures.

CAS registry number PubChem Dangerous Substances Directive (67/548/EEC) Critical point (thermodynamics) Flammability limit CRC Handbook of Chemistry and Physics Digital Object Identifier
240511
de