*3.5. Mechanical Characterization*

Tensile tests were carried out, at room temperature, on Haake type 3 dog-bone specimens by an MTS Criterion testing machine model 43 (MTS System Corporation, Eden Praire, MN, USA) equipped with a load cell of 10 kN. The instrument is interfaced to a computer running MTS Elite Software in order to record the results of the tensile tests. The gauge separation was set at 25 mm and the crosshead speed was 10 mm/min. The main mechanical properties were collected. Tests were conducted after 3 days from the samples injection moulding and during this time the specimens were stored in a dry keeper (SANPLATEC Corp., Osaka, Japan) in controlled atmosphere (room temperature and 50% humidity). At least 10 specimens were tested for each blend composition and the average values of the main mechanical properties were reported.

For the EWF characterization the SENT geometry was used. The SENT specimens were obtained from the injection molded Haake type 3 specimens appropriately cut (size: <sup>20</sup> × <sup>5</sup> × 1.5 mm3). SENT specimens with different crack length (from 1.5 mm up to 3.5 mm) were produced by sharp notch and during the cutting process, compressed air was used in order to avoid the "notch closing" phenomenon caused by excessive overheating generated by the cutter. The ligament length was checked by optical microscope. The tensile load to the SENT specimen was applied using the previous mentioned MTS Criterion testing machine at a crosshead speed of 0.5 mm/min. At least five samples for each ligament lengths were tested and the average values of the area under the load displacement curves were reported.

Dynamic mechanical thermal analysis (DMTA) was carried out using a Gabo Eplexor® DMTA (Gabo Qualimeter, Ahiden, Germany) with a 100 N load cell. At least three specimens were tested for each composition. The test bars (size: 20 × <sup>5</sup> × 1.5 mm3) were obtained by cutting the tensile specimens' dog-bone specimens. The samples bars were mounted on the machine in tensile configuration. The temperature range adopted for the test varied from −80 to 120 ◦C with heating rate of 2 ◦C/min and at a constant frequency of 1 Hz. The relaxation temperature, associated with the glass transition, was taken at the maximum of the peak of the damping factor (*tanδ*).
