Density and Viscosity of Glycolic, Lactic, and Malic Acid Esters

Densities and viscosities were measured as a function of temperature for 12 esters of glycolic, dl-lactic, and dl-malic acids and linear chain alcohols C1–C5. The density and kinematic viscosity were obtained using a pycnometer and a Pinkevitch capillary viscometer in a temperature range of 293.15–363.15 K with accuracies of 0.1 and 0.35%, respectively. The obtained data were used for dynamic viscosity calculation. It was demonstrated that the viscosity–temperature dependence of esters was described by the ASTM D341 model with an average absolute relative deviation of 1%. The temperature dependence of dynamic viscosity was fitted using the Arrhenius-like equation and Vogel–Fulcher–Tammann (VFT) model. It was found that the adjustable parameters A and B have the similar value for compounds in one homologous series. These parameters were taken as constant for each series of esters of the corresponding acids. The dynamic viscosity–temperature dependence of esters was better described by the VFT model than the Arrhenius-like equation. The capabilities of some group-additivity methods for predicting density have been reviewed and compared with experimental results.