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Keywords:

  • Dielectrics;
  • Equations of State;
  • High Pressure;
  • Liquids;
  • Thermodynamics

Abstract

The static dielectric permittivity, ϵ, and density, ϱ, of dichloromethane was measured from 303 to 423 K and from 10 to 200 MPa. Both quantities were determined simultaneously with the same samples in one autoclave which served as dilatometer and capacitor. The high pressure cell and auxiliary equipment are described. The ϵ-values vary between 5.36 at 423 K and 20 MPa and 10.01 at 303 K and 200 MPa. The new ϵ-results agree with existing literature data at 303 K but are about 2% higher than those for 323 K. Isotherms of ϵ increase almost linearly with ϱ. The density data are fitted with a modified Hayward equation. The recent Vedam-Limsuwan-Chen-equation correlates ϵ and ϱ and permits to calculate ϵ or ϱ with an uncertainty lower than the experimental error. With the Onsager-Kirkwood-Fröhlich equation a correlation factor g close the unity (1.1 to 1.2) is obtained.