Thermophysical and Excess Properties of Binary Mixtures of Dibutyl Ether and Components of Biodiesel

Densities, dynamic viscosities, and refractive indices for four binary mixtures formed by dibutyl ether with ethyl caprylate, ethyl caprate, ethyl laurate or ethyl myristate over the whole composition range were measured at T=(293.15–323.15 K) and atmospheric pressure. The excess molar volume (V_m^E), viscosity deviation (Δη), and refractive index deviation (Δn_D) for the four systems are calculated and then correlated to the Redlich–Kister polynomial. The V_m^E and Δη values are all negative over the entire range of mole fractions. The absolute values of V_m^E for the mixtures increase with increasing temperature and the absolute values of Δη decrease with increasing temperature. The Δn_D values with the volume fraction for the four binary systems are all positive over the entire composition range. The experimental results can provide reliable data for the compatibility of biodiesels and their blended fuels.