Kinetics of non-isothermal decomposition of cinnamic acid

The thermal stability and kinetics of decomposition of cinnamic acid were investigated by thermogravimetry and differential scanning calorimetry at four heating rates. The activation energies of this process were calculated from analysis of TG curves by methods of Flynn-Wall-Ozawa, Doyle, Distributed Activation Energy Model, Šatava-Šesták and Kissinger, respectively. There are only one stage of thermal decomposition process in TG and two endothermic peaks in DSC. For this decomposition process of cinnamic acid, E and logA[s−1] were determined to be 81.74 kJ mol−1 and 8.67, respectively. The mechanism was Mampel Power law (the reaction order, n = 1), with integral form G(α) = α (α = 0.1–0.9). Moreover, thermodynamic properties of ΔH≠, ΔS≠, ΔG≠ were 77.96 kJ mol−1, −90.71 J mol−1 K−1, 119.41 kJ mol−1.