*2.1. Materials*

For this study, a commercially available starch-based polymer, Mater-Bi® EI51N0 of Novamont, was studied. This bio-based and biodegradable polymer has a melt flow index (MFI) of 19 g/10 min (190 ◦C/2.16 kg) and a density of 1240 kg/m<sup>3</sup> (data provided by Novamont). This grade was selected for its properties, which are quite similar to polypropylene (PP), of high use in injection molding. Table 1 shows some properties of the as-received material.

**Table 1.** Properties of Mater-Bi® EI51N0 extract to datasheet supplied by Novamont.


Almond shell powder (ASP) with particle size between 0.05 and 0.125 mm provided by Hermen Europe, S.L. (Spain) was used for this study (Figure 1a). It consisted of a mixture of different almond shell varieties. Figure 1b shows that the predominant particle size range was about 0.08–0.125 mm. Table 2 shows the content of fixed carbon, volatile matter, humidity, ash, and the chemical composition of the main components of the used almond shell: hemicellulose, lignin, and cellulose, determined by thermogravimetric analysis (TGA) in previous work [10].

**Figure 1.** (**a**) Almond shell powder (ASP) powder, (**b**) Scanning electron microscope (SEM) image of ASP (×200 magnification and a scale marker of 100 µm).

**Table 2.** Content of moisture, volatile matter, fixed carbon ash, and composition of the used almond shell powder (ASP).


The compatibilization of starch polymer and ASP was carried out with epoxidized linseed oil (ELO), supplied by Traquisa S.L. (Spain). Some of its properties are shown in Table 3.

**Table 3.** Properties of epoxidized linseed oil (ELO) datasheet supplied by Traquisa.

