Developing biotechnological methods to produce glycolic acid and alkyl glycolates requires knowledge of thermophysical and thermodynamic data. Vapor pressures of linear alkyl glycolates HO–CH2–COO–(CH2) n –H with n = 1–8 were determined by the transpiration method. Standard molar enthalpies of vaporization at experimental temperature and at 298.15 K were derived from the temperature dependence of the vapor pressure. The critical temperatures and pressures of alkyl glycolates were measured by the pulse-heating method. The experimental data were successfully checked for internal consistency. Molar heat capacity of atmospheric pressure for liquid esters was measured by the method of differential scanning calorimetry in the temperature range 303–423 K. The molar liquid heat capacities at 298.15 K and atmospheric pressure of alkyl glycolates were calculated from the result of this work. The measured values were used for estimating prediction capabilities of group-contribution methods by Constantinou and Gani, Marrero and Gani, and Hukkerikar et al. for critical properties and Chickos and Acree, Domalski and Hearing, and Ceriani et al. for heat capacity at 298.15 K. Results of this study could be used for the design and optimization of the chemical processes of the utilization of renewable feedstock.

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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.