*2.5. Mechanical and Thermal Characterization*

Tensile tests were carried out on the ISO 527-1A extrusion molded specimen using an MTS Criterion model 43 (MTS Systems Corporation, Eden Prairie, MN, USA) universal testing machine. The MTS was equipped with a 10 kN load cell and the crosshead speed was set at 10 mm/min. Tensile tests were performed, at room temperature, after 3 days after the sample injection molding and during this time, the sample were stored in a dry keep at 25 ◦C and 50% of relative humidity. At least six specimens for each composition were tested.

Charpy impact tests were carried on the injection molded specimen pre-notched with a V-notch of 2 mm. A CEAST 9050 machine (INSTRON, Canton, MA, USA) was used and at least six specimens, at room temperature, were tested. The impact tests, also in this case, were carried out after 3 days of the injection molding keeping the samples in a controlled atmosphere.

The main biocomposites; thermal properties were calculated by differential scanning calorimetry (DSC) using a Q200-TA DSC (TA Instruments, New Castle, DE, USA) equipped with an RSC 90 cooling system. Nitrogen was used as purge gas set at 50 mL/min. Few milligrams (about 12 mg) were cut from the injection molded samples and the heating program was set in order to consider the thermal history of the samples and thus considering the injection molding history. In this way it was possible to calculate the crystallinity reached by the samples after the injection molding process. The thermal program was: heating at 10 ◦C/min from room temperature up to 200 ◦C, the final temperature was kept for 1 min. The melting and crystallization temperatures were calculated in correspondence of the maximum and minimum of the melting peak and cold crystallization peak, respectively. As far as the melting and cold crystallization enthalpies were concerned, they were calculated integrating the peak areas of the melting and crystallization peaks, respectively. The

PLA crystallinity percentage of PLA was calculated according to the following equation (Equation (1)) [27]:

$$X\_{\rm cc} = \frac{\Delta H\_{\rm m} - \Delta H\_{\rm cc}}{\Delta H^{\circ}\_{\rm m} \cdot wt. \% \text{PLA}} \tag{1}$$

where, Δ*Hm* and Δ*Hcc* are the melting and cold crystallization PLA enthalpies of PLA, Δ*H*◦ *m* is the theoretical melting heat of 100% crystalline PLA (taken equal to 93 J/g [35]).
