*3.4. Samples Preparation*

PLA/PBSA blends were prepared using an Haake Minilab II (Thermo Scientific Haake GmbH, Karlsruhe, Germany) co-rotating conical twin-screw mini-extruder. Before processing the materials were dried in an air circulated oven at 60 ◦C for 1 day. For each extrusion cycle about 6 g of material, manually mixed with the additives, were fed into the mini extruder at 190 ◦C and 110 rpm. Subsequently the molten material was transferred, through a preheated cylinder, to a Thermo Scientific Haake MiniJet Mini-Injection Molding System for preparation of tensile dog-bone specimens (Haake bar type 3 with gauge dimensions: <sup>25</sup> × <sup>5</sup> × 1.5 mm3). The cylinder temperature was set equal to the extrusion temperature (190 ◦C) while the mold temperature was set at 50 ◦C. In order to completely fill the mold, 300 bar of pressure for 15 sec was set followed by a post pressure of 200 bar for 4 sec.

The blends compositions are listed in Table 1. On the basis of a previous work [18] a PLA/PBSA matrix containing 60 wt.% of PLA and 40 wt.% of PBSA was selected. The matrix was plasticized with Triacetin maintaining fixed the ratio between the matrix and the plasticizer (equal to 9), for all the formulations. The ratio between the matrix and plasticizer was set on the basis of literature work [40–42,64] in order to ensure a good processability and a high flexibility to counterbalance the effect of fiber addition that tend to embrittle the matrix.

**Table 1.** Blends name and compositions.

