The thermophysical properties of diethylene glycol dimethyl ether blended with the fatty acid methyl esters

Densities, dynamic viscosities, and refractive indices for four binary mixtures formed by diethylene glycol dimethyl ether with four fatty acid methyl ester (methyl octanoate, methyl decanoate, methyl dodecanoate and methyl tetradecanoate) over the whole composition range were measured at T =(293.15 to 323.15)K and atmospheric pressure. The excess molar volume ( V _m ^E ), viscosity deviation (Δ η ), and refractive index deviation (Δ n _D ) for the four systems are calculated and then correlated to the Redlich − Kister polynomial. The V _m ^E values are all positive for the four binary systems over the entire range of mole fractions, while the Δ η and Δ n _D values are all negative. The experimental results of the mixtures of ether-fatty acid methyl ester can provide reliable data for the compatibility of biodiesels and their blended fuels.