BIBLIOS

Document type
Journal articles

Document subtype
Full paper

Title
Dielectric Properties of 1,1,1,3,3-Pentafluoropropane (HFC-245fa)†

Participants in the publication
Anely N. Gurova (Author)
FACULDADE DE CIÊNCIAS DA UNIVERSIDADE DE LISBOA
Filipe E. de Brito (Author)
INSTITUTO SUPERIOR TÉCNICO
Carlos A. Nieto de Castro (Author)
Dep. Química e Bioquímica
CQE
Umesh V. Mardolcar (Author)
INSTITUTO SUPERIOR TÉCNICO

Summary
The relative permittivity of 1,1,1,3,3-pentafluoropropane (HFC-245fa), a liquid hydrofluorocarbon developed as a blowing agent for plastic foams, is reported. This fluid is being evaluated as a potential replacement for HCFC-141b (1,1-dichloro-1-fluoroethane). The relative permittivity of HFC-245fa in the liquid phase was measured using the direct capacitance method at temperatures from (217 to 303) K and at pressures up to 16 MPa, for a frequency of 10 kHz. The uncertainty of the dielectric constant measurements is estimated to be ±0.88 × 10-2. A complete set of values of the relative permittivity as a function of temperature, pressure, and density is presented that covers the needs for most engineering applications. The results were correlated by polynomial equations as a function of density and temperature and also as a function of pressure and temperature. To study the dependence of relative permittivity on density and temperature on a molecular basis, the theory developed by Vedam et al. and adapted by Diguet was applied to analyze the data. The Kirkwood modification of the Onsager equation was used to obtain the value of its dipole moment in the liquid phase. The apparent dipole moment obtained was μ* = 2.688 D.


Institution
FACULDADE DE CIÊNCIAS DA UNIVERSIDADE DE LISBOA

Where published
Journal of Chemical & Engineering Data

Publication Identifiers

Publisher
American Chemical Society (ACS)



Document Identifiers
DOI - https://doi.org/10.1021/je000250v
URL - http://dx.doi.org/10.1021/je000250v

Keywords
dipole moment HFC-245fa 1 1 1 3 3-pentafluoropropane relative permittivity Kirkwood equation Vedam equation

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