Click for PDF View TDS
Technical Data Sheet
Dimethylacetamide (DMAc)


Chemical Synonym
  • Dimethylacetamide; DMAc
Applications
  • HTF - pharmaceutical processing
  • Fibers
  • Process solvents

Product Description

Dimethylacetamide (DMAc) is a colorless, high boiling, polar, hygroscopic liquid. DMAC is a good solvent for a wide range of organic and inorganic compounds and it is miscible with water, ethers, esters, ketones and aromatics compounds. It is used in the production of polyacrylonitrile and polyurethane based fibers, films and coatings. The polar nature of DMAC enables it to act as a combined solvent and reaction catalyst in many reactions producing high yields and pure product in short time periods.

DMAC is a dipolar aprotic solvent used for many organic reactions and industrial applications. It is a versatile solvent due to its high boiling point and good thermal and chemical stability.

1. Acrylic fibres
DMAC is applied as solvent in wet spinning processes for the production of acrylic fibres.

2. Elasthane fibres
In the production of polyurethane-based elasthane fibres, DMAC is the solvent of choice given its evaporation speed, whether it is used in wet or dry spinning processes.

3. Pharmaceuticals
DMAC can be used both as a solvent and as a reagent in the production of various pharmaceuticals. In the production of novel x-ray contrast media, DMAC is used as a solvent. Cephalosporins, which are among one of the leading classes of antibiotics, are partly produced from derivatives of 7-ADCA (7-aminodeacetoxy-cephalosporanic acid). DMAC is used in the manufacturing process.

4. Various polymers
DMAC is a good solvent for polyimide resins, both in coating and film production. It is also the ideal solvent for the production of dialyser membranes, based on polysulfones. A mixture of DMAC and lithium chloride is a useful solvent for cellulose fibres in several applications.



Typical Properties

PropertyTypical Value, Units
General
Molecular FormulaC4H9NO
Molecular Weight87.12 g/mol
Autoignition Temperature345 °C
Boiling Point166 °C
Density 
     @ 20°C0.942 g/cm3
     @ 40°C0.923 g/cm3
Dielectric Constant 
     10 kHz @ 25°C37.8
Dipole moment3.7 D (debye)
Dissociation constant, pKa 
     @ 25°C-0.19
Evaporation Ratea172
Flash Point 
     Closed Cup64 °C
Free energy of formation 
     @ 25°C288 kJ/mol
Freezing Point-20 °C
Hansen solubility parameters @ 25°C 
     Dispersion7.87 (MPa)½
     Hydrogen Bonding10.2 (MPa)½
     Polar11.5 (MPa)½
     Total22.7 (MPa)½
Heat of Combustion25.45 kJ/mol
Heat of Vaporization 
     @ 25°C53.2 kJ/mol
Octanol-water partition coefficient, log Pow 
     @ 25°C-0.77
pH 
     @ 200 g/l4-7
Refractive Index1.4380
Specific Heat 
     @ 20°C0.175 kJ/mol.K
Surface Tension 
     @ 20°C33.8 mN/m
     @ 40°C30.9 mN/m
     @ 60°28.3 mN/m
Thermal Conductivity 
     @ 20°C169.2 mW/m.K
     @ 40°C161.2 mW/m.K
     @ 60°C153.3 mW/m.K
Vapor Density 
     (air = 1)3.02
Vapor Pressure 
     @ 20°C1.78 hPa
     @ 21.7°C2 hPa
     @ 40°C6.6 hPa
     @ 60°C20.16 hPa
Viscosity 
     @ 20°C1.02 mPa·s
     @ 25°C0.92 mPa·s
     @ 40°C0.78 mPa·s
     @ 60°C0.62 mPa·s
Water solubilityMiscible

aDIN 53170, ether=1



Principal chemical properties
The chemical reactions of DMAc are typical of those of disubstituted amides. Under suitable conditions, DMAc will react as follows:

Hydrolysis in the Presence of Strong Acids
CH3CON(CH3)2 + H2O + HCI -> CH3COOH + (CH3)2NH.HCI

Saponification in the Presence of Strong Bases
CH3CON(CH3)2 + NaOH -> CH3COONa + (CH3)2NH

Alcoholysis in the Presence of Hydrogen Ions
CH3CON(CH3)2 + ROH -> CH3COOR + (CH3)2NH



Viscosities of resins in DMAc

Coating resins

Viscosity (at 25°C,
15w% solution (mPa.s= cP))

Acrylic resins

Acryloid®(a)
  A-21
  A-107
  B-72


23
23
20

Lucite®(b)
  44
  45
  46


26
38
30

Epoxy resins

Epon®(c)
  1001
  1002
  1004
  1007


5
6
7
10

Cellulose resins

Half sec butyrate
EAB-500-1(d)
EAS-171-2(d)

555
950
1275

Urea-Formaldehyde

Uformite®(e)
  F-222

20

Melamine-Formaldehyde

MM-55

15

Vinyl resins

VYHH(f)
VAGH(f)
VMCH(f)
Geon® 121(g)
Geon® 101(g)

52
53
48
230
3500

Nitrocellulose resins

HB-14 Nitrocellulose

18


(a) Rohm and Haas
(b) Reduced to 5%w%
(c) DuPont
(d) Shell Chemicals
(e)Cytec Technology Corp.
(f) Union Carbide
(g) BF Goodrich



Compatibility and Solubility

DMAC is completely miscible with water, ethers, esters, ketones and aromatic compounds. Unsaturated aliphatics are highly soluble but saturated aliphatics have a limited solubility.

Solvent

Solubility (25°C)

Iso-octane

33 g / 100 g DMAc

Di-isobutylene

Completely miscible

N-Hexane

Completely miscible

N-heptane

31 g / 100 g DMAc

Cyclohexane

Completely miscible

Cyclohexene

Completely miscible

Kerosene

16 g / 100 g DMAc



Packaging
  • Bulk
  • PE drums (200 kg net)
  • Iron drums (195 kg net)
  • IBC containers (950 kg net)



Eastman and its marketing affiliates shall not be responsible for the use of this information, or of any product, method, or apparatus mentioned, and you must make your own determination of its suitability and completeness for your own use, for the protection of the environment, and for the health and safety of your employees and purchasers of your products. No warranty is made of the merchantability of fitness of any product, and nothing herein waives any of the Seller's conditions of sale.