Methyl acetate Methyl acetate
Structural formula
| Business number | 01PH |
|---|---|
| Molecular formula | C3H6O2 |
| Molecular weight | 74.08 |
| label |
Methyl acetate, Acetic acid Methyl ester, Methyl ethanoate, oil extractant, Quick drying solvent |
Numbering system
CAS number:79-20-9
MDL number:MFCD00008711
EINECS number:201-185-2
RTECS number:AI9100000
BRN number:1736662
PubChem number:24869630
Physical property data
1. Properties: colorless and transparent liquid with fruity aroma. [1]
2. Melting point (℃): -98.1[2]
3. Boiling point (℃): 56.8[3]
4. Relative density (water=1): 0.93 (20℃)[4]
5. Relative vapor density (air = 1): 2.6[5]
6. Saturated vapor pressure (kPa): 21.7 (20℃)[6]
7. Heat of combustion (kJ/mol): -1592.7[7]
8. Critical temperature (℃): 233.7[8]
9. Critical pressure (MPa): 4.69[9]
10. Octanol/water partition coefficient: 0.18[10]
11. Flash point (℃): -10 (CC); -5.6 (OC) [11]
12. Ignition temperature (℃): 454[12]
13. Explosion upper limit (%): 16.0[13]
14. Lower explosion limit (%): 3.1[14]
15. Solubility: slightly soluble in water, miscible in ethanol and ether and most organic solvents. [15]
16. Viscosity (mPa·s, 20ºC): 0.385
17. Flash point (ºC, closed): -10
18. Flash point (ºC, open cup): -16
19. Heat of evaporation (KJ/mol, 56.3ºC): 30.43
20. Heat of generation (KJ/mol): 414.91
21. Specific heat capacity (KJ/(kg·K), 18~42ºC, constant pressure): 2.10
22. Boiling point rising constant: 2.061
23. Electrical conductivity (S/m, 20ºC): 3.4×10-6
24. Thermal conductivity (W/(m·K) , 12ºC): 0.17104
25. Volume expansion coefficient (K-1, 20ºC): 0.00139
26. Relative density (20℃, 4℃ ): 0.9342
27. Relative density (25℃, 4℃): 0.9473
28. Critical density (g·cm-3): 0.325
29. Critical volume (cm3·mol-1): 228
30. Critical compression factor: 0.257
31. Eccentricity factor: 0.325
32. Lennard-Jones parameter (A): 10.86
33. Lennard-Jones parameter (K): 173.3
p>
34. Solubility parameter (J·cm-3)0.5: 19.435
35. van der Waals area (cm2·mol-1): 6.440×109
36. van der Waals volume (cm3 ·mol-1): 42.540
37. Liquid phase standard combustion heat (enthalpy) (kJ·mol-1): -1592.0
38. Liquid phase standard claimed heat (enthalpy) (kJ·mol-1): -445.8
39. Liquid phase standard hot melt (J·mol-1·K-1): 140.8
40. Gas phase standard combustion heat (enthalpy) (kJ·mol -1): -1625.9
41. Gas phase standard claims heat (enthalpy) (kJ·mol-1): -411.9<Using sulfuric acid as a catalyst, the esterification reaction is directly carried out to produce crude methyl acetate, which is then dehydrated with calcium chloride, neutralized with sodium carbonate, and fractionated to obtain the finished product.
Refining method: due to methyl acetate Easily hydrolyzed, the main impurities are free acetic acid and methanol. The presence of methanol can be seen from its solubility in water. Methyl acetate dissolves 24% in water at room temperature. It is miscible with water if 1% methanol is present. During purification, 85 mL of acetic anhydride was added to 1000 mL of methyl acetate, and the mixture was refluxed for 6 hours and then fractionated. Acidic impurities can be shaken with anhydrous potassium carbonate and then distilled away. Methanol can also be removed by treatment with acetyl chloride. High-purity methyl acetate can be washed with concentrated brine, dried with calcium oxide or magnesium sulfate, and then distilled and refined.
2. Add acetic acid, methanol, and sulfuric acid in an enamel tank and reflux for 8 hours to react, then steam the crude product, first use solid calcium chloride to remove most of the water, and then use solid sodium carbonate to remove the acidity. Neutral dry with anhydrous potassium carbonate, then fractionate, collect the 55-58°C fraction, which is the finished product.
Purpose
1. Quick-drying solvents of nitrocellulose and cellulose acetate, used in paints and coatings.
2. Used in the manufacture of artificial leather and spices and as an extraction agent for oils and fats. It is also a raw material for making dyes and medicines.
3. Used as a spice, a quick-drying solvent for nitrocellulose and cellulose acetate, and an extractant for oils and fats.
4. It can be used in daily chemical flavor formulations, but most importantly in food flavor formulations.
5. Used as solvent, essence and reagent for making spray paint, artificial leather, etc. [27]