Investigation of the thermal behavior of trielaidin between 10 K and 360 K

Heat capacities of the α- and the β-phase of trielaidin were measured from 10 to 360 K. The enthalpy of fusion of the stable β-phase was found to be 177.4 J·g-1, the triple point temperature was 314.83 K, and the calculated purity, assuming eutectic behavior of the main component and the impurity, was 96.66 mol %. The enthalpy of fusion of the metastable α-phase was calculated to be 95.1 J·g-1; the melting temperature was estimated to be 288 K from differential scanning calorimetry experiments. The heat capacity of the liquid phase can be given by a simple linear fit between 320 K and 360 K:  cp(l) = (1.327 + 0.002529T/K) J·K-1·g-1. To obtain a thermodynamically consistent set of entropy and enthalpy data for both forms, a zero entropy of 0.037 J·K-1·g-1 and a zero enthalpy of 41.48 J·g-1 had to be used for the α-phase. The origin of these values is discussed.