Dielectric Study and molecular interaction of (1,3-propanediol + 2-butanone) binary liquid mixtures at different temperatures

Relative permittivity of a material is an intrinsic property that plays an important role in characterizing molecular structure, molecular interactions (homo- and hetero-) and molecular ordering in liquid solutions [1]. In general, type of solvent, solution constituent, concentration and temperature are the most important factors, whichinfluence dielectric properties and dipole moments of liquids [2]. Propanediols are three carbon diols that have many industrial and biological applications [5]. Due to the presence of two –OH groups in the molecule, the dielectric behavior of this group of the organic compounds is strongly influenced by intermolecular and intramolecularhydrogen bond formation [3].This study determined the experimental relative permittivity data for the (1,3-propanediol + 2-butanone) binary system as a function of composition at T = (298.2 and 308.2) K. In this work, the excess parameters such as the excess permittivity and the excess Helmholtz energy were calculated. The results are discussed in terms of homo and hetero interactions and structure of the studied binary mixtures.In this binary system, the excess permittivity values were negative over the whole composition range, which indicates the formation of multimer structures as a consequence of intermolecular interactions between the components. The interaction is mainly through hydrogen bonding between the 1,3-propanediol and 2-butanone molecules.