Dielectric study of primary alkanediols (C3, C4, C5) with 1-pentanol isomers

Relative permittivities and refractive indices were measured for the several polar binary systems containing straight-chain primary diols and primary pentanol isomers over the whole composition range at 298.15 K and atmospheric pressure. The pentanol isomers were 1-pentanol (amyl alcohol), 3-methyl-1-butanol (isoamyl alcohol), and 2-methyl-1-butanol (active amyl alcohol). The chosen diols were 1,3-propanediol, 1,4-butanediol, and 1,5-pentanediol. The excess parameters, i.e. excess permittivity, excess Helmholtz energy and excess Kirkwood correlation factor, were determined. The Reis-Ιglesias formulation was used to obtain information on the molecular interactions and structure in these binary systems.