2.4.5. Combustion Characteristics Indices

The indices, ignition temperature (Ti), the temperature at the maximum DTG (Tmax), the burnout temperature (Tb), the corresponding time (ti, tmax, tb), and the maximum and average DTG (−Rp and −Rv), can be obtained from the TGA data [1,8]. These were subsequently used to monitor the combustion characteristics, comprehensive combustibility (S), flammability (C), ignition (Di), and burnout (Db), according to the relations in Equations (9)–(12).

$$\mathbf{S} = \frac{-\mathbf{R\_P} \times -\mathbf{R\_V}}{\mathbf{T\_i^2} \times \mathbf{T\_b}} \tag{9}$$

$$\mathbf{C} = \frac{-\mathbf{R\_{P}}}{T\_{i}^{2}} \tag{10}$$

$$\mathbf{D}\_{\mathbf{i}} = \frac{-\mathbf{R}\_{\mathbf{p}}}{\mathbf{t}\_{\mathbf{i}} \times \mathbf{t}\_{\mathbf{p}}} \tag{11}$$

$$\mathbf{D\_b = \frac{-\mathbf{R\_P}}{\Delta \mathbf{t}\_{1/2} \times \mathbf{t\_P} \times \mathbf{t\_b}}} \tag{12}$$

#### 2.4.6. Thermodynamic Analysis

The thermodynamic parameters [change in enthalpy (ΔH, J/mol), Gibbs free energy (ΔG, J/mol), and entropy (ΔS,J/((mol\*K)))] were deduced as functions of conversions from the kinetic parameters, as shown in Equations (13)–(15).

$$
\Delta H = E\_{\theta} - RT \tag{13}
$$

$$
\Delta G = E\_{\theta} + RT\_{\text{max}} \ln \left( \frac{k\_B T\_{\text{max}}}{hA\_{\theta}} \right) \tag{14}
$$

$$
\Delta S = \frac{\Delta H - \Delta G}{T\_{\text{max}}} \tag{15}
$$

where *kB*, and *<sup>h</sup>* are the Boltzmann constant (1.381 × <sup>10</sup>−<sup>23</sup> J/K) and the Planck constant (6.626 × <sup>10</sup>−<sup>34</sup> J s), respectively.

#### **3. Results and Discussion**
