perfluorooctanoic acid
Structural formula
| Business number | 04A6 |
|---|---|
| Molecular formula | C8HF15O2 |
| Molecular weight | 414.07 |
| label |
Pentafluorooctanoic acid, Pentafluorooctanoic acid monohydrate, Pentafluorooctacarbonic acid, 15 PFOA, 15 PFOA single hydrate, 15 F 8 carbonate, Dispersants, emulsifiers |
Numbering system
CAS number:335-67-1
MDL number:MFCD00004174
EINECS number:206-397-9
RTECS number:RH0781000
BRN number:1809678
PubChem number:24887130
Physical property data
Characteristics: white crystal, highly acidic.
Density (g/mL, 25/4℃): 1.792
Melting point (ºC): 52-56
Boiling point (ºC, normal pressure): 189
Solubility: Solubility in water is 0.01~0.023mol/L
Surface tension: 7.9mN/m
Toxicological data
is a strong acid and inhaling its gas will cause Congestion of throat. Can corrode skin.
Ecological data
Other harmful effects: This substance has The environment may be hazardous and special attention should be paid to water bodies.
Molecular structure data
1. Molar refractive index: 42.89
2. Molar volume (cm3/mol): 237.2
3. Isotonic specific volume (90.2K ): 480.4
4. Surface tension (dyne/cm): 16.8
5. Polarizability (10-24cm3): 17.00
Compute chemical data
1. Reference value for hydrophobic parameter calculation (XlogP): 4.9
2. Number of hydrogen bond donors: 1
3. Number of hydrogen bond acceptors: 17
4. Number of rotatable chemical bonds: 6
5. Number of tautomers: none
6. Topological molecule polar surface area 37.3
7. Number of heavy atoms: 25
8. Surface charge: 0
9. Complexity: 530
10. Number of isotope atoms: 0
11. Determine the number of atomic stereocenters: 0
12. Uncertain number of atomic stereocenters: 0
13. Determine the number of chemical bond stereocenters: 0
14. Number of uncertain chemical bond stereocenters: 0
15. Number of covalent bond units: 1
Properties and stability
White scaly crystals.
This product is highly acidic, and its vapor can irritate the skin, eyes and mucous membranes. It can be released when heated to 250°C.Toxic gases. Production equipment should be sealed, the workshop should be well ventilated, and operators should wear protective equipment.
Storage method
This product should be kept sealed. It should be stored in a dry, clean, and dark place, and the room temperature should not be higher than 40°C. Strong vibrations should be avoided during transportation, and they should not be turned upside down when stacked.
It should be stored in glass or corrosion-resistant alloy stainless steel and aluminum containers and tightly sealed. Store in a cool, dry and ventilated warehouse. Keep away from heat sources, sun protection and moisture-proof.
Synthesis method
In the electrolytic cell of the electrode group consisting of alternating nickel anodes and iron cathodes, add anhydrous liquid hydrogen fluoride, octanoyl chloride and a small amount of n-butylmercaptan. After mixing evenly, apply 2500A direct current. In order to maintain the concentration of the electrolyte during the electrolysis process, octanoyl chloride needs to be continuously added. The electrolytic products are insoluble in the electrolyte and sink to the bottom of the electrolytic tank, and need to be released after a certain period of time. The electrolyte temperature is controlled at 24°C. The voltage is controlled between 5 and 8V for electrolysis operation. The gas generated during the electrolysis process is cooled and condensed by the condenser to below -30°C, and then pressurized by the buffer and water to maintain the system at a pressure of 0.042MPa, and then the gas is vented. The electrolyzed product is neutralized with sodium hydroxide and acidified with sulfuric acid, and then sent to the distillation tower for distillation. The fraction with 1.33kPa and 91.5~93.5℃ is collected as the finished product.
Electrolysis:
Esterification:
2. Put the raw materials octanoyl chloride (purity 99.5%), hydrogen fluoride and a small amount of n-butyl sulfuric acid into the electrolytic cell, energize at 20~25℃ (voltage 5~8), electrolysisThe product is neutralized with alkali, acidified with acid, and distilled to obtain perfluorooctanoic acid.
Purpose
1. Mainly used for making derivatives. Its sodium salt and ammonium salt are excellent dispersants for the synthesis of fluorine-containing polymers such as polytetrafluoroethylene, 1# fluororubber, 2# fluororubber, and its complexes and acrylic acid synthesis. The polymer is a good hydrophobic and oil-repellent agent, and its ester derivatives are used as chromatographic fixatives. 2. Mainly used as a dispersant during the polymerization of polytetrafluoroethylene, fluororubber, etc., and also as a raw material for the preparation of fluorine-containing surfactants.