Calculation of dielectric constant for polymers and some organic solvents

A calculation scheme for quantitative estimation of the dielectric constant of polymers and organic solvents was developed on the basis of a modified Clausius-Mossotti equation. The calculation rakes into account the chemical structure of an organic liquid molecule or a polymer repealing unit. In the case of polymers it is found that a contribution of the dipole orientational polarization to the total polarization depends on the chemical structure of the polar group, but is independent of the van der Waals volume of the repeating unit. For organic liquids, the contribution to the dipole orientational polarization depends substantially both on the type of the polar group and on the van der Waals volume of a molecule incorporating this polar group. Some relationships for this contribution of the molecular van der Waals volume are proposed. Their substitution into the modified Clausius-Mossotti equation gives the values which agree with the experimental data, the accuracy being sufficient for practical calculations.