Temperature-composition values of liquid-solid equilibrium were measured calorimetrically and tabulated for 10 binary solutions of these 5 organic carbonates: ethylene carbonate, propylene carbonate, dimethyl carbonate, ethyl methyl carbonate, and diethyl carbonate. Further, heat capacity (C-p) and temperature (T-m) and enthalpy (Delta(fus)H) of fusion were measured for the five carbonates, with the C-p values fitted with polynomial functions. Based on these T-m and Delta(fus)H values and polynomial functions of C-p, the binary phase diagrams were fitted with thermodynamic nonideal solution models for an evaluation of the model parameters. The results of the evaluation were tabulated and discussed as an indication of the nature and strength of the molecular interactions between different carbonates. These interactions were shown to determine many of the important features of the binary phase diagrams.