Heat capacities and thermodynamic properties of fenpropathrin (C22H23O3N)

The heat capacities of fenpropathrin in the temperature range from 80 to 40 0 K were measured with a precise automatic adiabatic calorimeter. The fenpr opathrin sample was prepared with the purity of 0.9916 mole fraction. A sol id-liquid fusion phase transition was observed in the experimental temperat ure range. The melting point, T-m, enthalpy and entropy of fusion, Delta H- fus(m), Delta S-fus(m), were determined to be 322.48,0.01 K, 18.57,0.29 kJ mol(1) and 57.59,1.01 J mol(1) K-1, respectively. The thermodynamic functio ns of fenpropathrin, H-(T)-H-(298.15), S-(T)-S-(298.15) and G((T))-G((298.1 5)), were reported with a temperature interval of 5 K. The TG analysis unde r the heating rate of 10 K min(1) confirmed that the thermal decomposition of the sample starts at ca. 450 K and terminates at ca. 575 K. The maximum decomposition rate was obtained at 558 K. The purity of the sample was dete rmined by a fractional melting method.