Technical Abstract: The present study examines the thermal properties of melting and solidification for binary mixtures between dodecyl carbonate (1a), tetradecyl carbonate (1b), hexadecyl carbonate (1c), and octadecyl carbonate (1d) by differential scanning calorimetry (DSC) in order to gain further understanding of the solid-liquid transitions in mixtures of these materials. Six combinations of binary carbonate mixtures were examined at various weight fraction ratios and sharp well defined phase transitions were observed at 80:20, 88:12, and 90:10, for (1a:(1b,1c,1d), respectively, at 74:26 and 80:20 for 1b:(1c, 1d), respectively, and at 82.5:17 for 1c:1d. The melting and solidification temperatures for these optimal mixtures ranged between 15-39 oC for melting and 9-33 oC for solidification, respectively. The latent heat of melting and solidification were determined for the eutectic compositions for the binary carbonate mixtures and were found to range between 150-193 J g-1. These carbonate mixtures extend the thermal properties of the pure oleochemical carbonates and compliment other biobased PCM substances such as fatty acids, esters, and alcohols and may provide useful biobased alternatives to paraffin wax and salt hydrate PCM currently dominating the market.