*2.5. Thermal Analysis of PLA Formulations Plasticized with MBNO and MHO*

The thermal properties of PLA and plasticized PLA compositions were determined by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The glass transition temperature (Tg), cold crystallization temperature (Tcc) and melting temperature (Tm) were obtained by DSC with a Mettler Toledo DSC 821 (Schwerzenbach, Switzerland). The test conditions were under nitrogen atmosphere (flow rate 66 mL·min−<sup>1</sup> ) with a thermal program to remove thermal history consisting of a first heating from 30 ◦C to <sup>200</sup> ◦<sup>C</sup> at 10 ◦C·min−<sup>1</sup> , followed by a cooling to 30 ◦C at 2 ◦C·min−<sup>1</sup> and a last heating to <sup>350</sup> ◦C at 2 ◦C·min−<sup>1</sup> . Thermal transitions were determined from the second heating. The percentage crystallinity of each material was calculated using the following equation:

$$X\_{\rm c} \left(\%\right) = \frac{\Delta H\_{\rm m} - \Delta H\_{\rm c}}{w \Delta H\_{\rm m}^{\rm o}} \times 100\tag{2}$$

where ∆*H<sup>m</sup>* is the enthalpy of fusion, ∆*H<sup>c</sup>* the cold crystallization enthalpy, *w* the mass fraction of the material and ∆*H<sup>o</sup> <sup>m</sup>* the enthalpy of fusion for a theoretical pure crystalline PLA structure, which was assumed to be 93 J g−<sup>1</sup> [34].

TGA tests were carried out to determine the initial degradation temperature (T0) and the maximum degradation temperature (Tmax). The equipment used was a TGA/SDTA 851 from Mettler Toledo (Schwerzenbach, Switzerland) and the samples (7–10 mg) were tested under nitrogen atmosphere (flow rate 66 mL·min−<sup>1</sup> ) and heating from 30 ◦C to 700 ◦C at <sup>20</sup> ◦C·min−<sup>1</sup> . T<sup>0</sup> was determined at 5% mass loss, while Tmax was calculated from the first derivate of the TGA curves (DTG).
