Thermodynamic investigation of several natural polyols (IV): Heat capacities and thermodynamic properties of adonitol

Adonitol was investigated by adiabatic calorimetry (AC), differential scanning calorimetry (DSC), thermogravity analysis (TGA) and oxygen-bomb combustion calorimetry. The heat capacity was precisely measured in the temperature range from 78 to 400 K by means of a small sample automated adiabatic calorimeter. The melting temperature, the molar enthalpy and entropy of this transition were determined to be T = 369.08 ± 0.45 K, 36.42 ± 0.18 kJ mol−1 and 98.68 ± 0.49 J K−1 mol−1 respectively from the experimental Cp–T   curve. The thermodynamic functions [HT0−H298.150] and [ST0−S298.150], were derived from the heat capacity data with an interval of 5 K. The standard molar enthalpy of combustion and formation of the compound have been determined to be ΔcHm0   (C5H12O5,cr)=(−2562.4±1.3) kJ mol−1 and ΔfHm0   (C5H12O5,cr)=(−1120.1±1.5)  kJ mol−1 respectively by means of a precision oxygen-bomb combustion calorimeter at T = 298.15 K. The thermostability of the compound was further studied by DSC and TGA measurements.