Dielectric Constant of some common Liquids

Common fluids and their dielectric constant or permittivity

The Dielectric Constant, or permittivity - ε - is a dimensionless constant that indicates how easy a material can be polarized by imposition of an electric field on an insulating material. The constant is

the ratio between the actual material ability to carry an alternating current to the ability of vacuum to carry the current.

The dielectric constant can be expressed as

ε = εs / ε0         (1)

where

ε = the dielectric constant

εs = the static permittivity of the material

ε0 = vacuum permittivity

The Dielectric Constant of common fluids are indicated in the table below. The Dielectric Constant is in general influenced by 

  • temperature
  • moisture levels
  • electrical frequency
  • part thickness
Fluid Temperature
(oF)
Dielectric Constant
ε -
Acetic Acid 68 6.2
Acetone 77 20.7
Air (at STP, for 0.9 MHz)) 1.00058986 ± 0.00000050
Alcohol, ethyl (ethanol) 77 24.3
Alcohol, methyl (methanol) 68 33.1
Alcohol, propyl 68 21.8
Ammonia (aqua) 68 16.5
Aniline 68 7.3
Benzene 68 2.3
Bromine 68 3.1
Butane 30 1.4
Caproic acid 160 2.6
Carbon disulfide   2.64
Carbon tetrachloride 68 2.23
Castor Oil 60 4.7
Chlorine 32 2.0
Chloroform 68 4.8
Cotton seed oil   3.1
Cresol 63 10.6
Cumene 68 2.4
Decane 68 2.0
Dodecane 68 2.0
Ether 68 4.3
Ethylamine 70 6.3
Ethylene glycol 68 37.0
Fluorine (freon) refrigerant R-11 77 2.0
Fluorine refrigerant R-12 77 2.0
Fluorine refrigerant R-22 77 2.0
Furan 77 3.0
Furfural 68 42.0
Gasoline 70 2.0
Glycerine   47-68
Glycerol 77 42.5
Heptane 68 1.9
Hexane -130 2.0
Hexanol 77 13.3
Hydrazine 68 52.0
Jet fuel 70 1.7
Kerosene 70 1.8
Linoleic Acid 32 2.6-2.9
Linseed Oil   3.2-3.5
Mercury (vapor) 298 1.00074
Methane -280 1.7
Napthalene 68 2.5
Octane 68 2.0
Olive Oil 68 3.1
Oxygen -315 1.51
Palmitic Acid 160 2.3
Pentane 68 1.8
Phenol 50 4.3
Phosgene 32 4.7
Pinene 68 2.7
Propane 32 1.6
Propylene   11.9
Pyridine 68 1.12
Resorcinol   3.2
Stearic Acid 160 2.3
Styrene 77 2.4
Terpinene 70 2.7
Toluene   2.0-2.4
Turpentine (wood) 68 2.2
Vacuum (by definition) 1
Water 68 80.4

Typical dielectric values for some common plastic materials are indicated below:

Plastic Material Dielectric Constant
ε -
Acetal 3.7 - 3.9
Acrylic 2.1 - 3.9
ABS 2.9 - 3.4
Nylon 6/6 3.1 - 8.3
Polycarbonate 2.9 - 3.8
Polyester, TP 3.0 - 4.5
Polypropylene 2.3 - 2.9
Polysulfone 2.7 - 3.8
PPO, Modified 2.4 - 3.1
Polyphenylene sulfide 2.9 - 4.5
Polyacrylate 2.6 - 3.1
Liquid Crystal 3.7 - 10

Related Topics

  • Material Properties - Material properties - density, heat capacity, viscosity and more - for gases, fluids and solids

Related Documents

    Key Words

    • en: dielectric constants fluids liquids
    • es: constantes dieléctricas Fluidos Líquidos
    • de: dielektrischen Konstanten Flüssigkeiten Flüssigkeiten

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