The European Commission promotes the increase of recycled plastic in short-term applications as its strategy to introduce plastic products into a circular economy model. However, the mechanical recycling process could reduce the thermal stability and mechanical properties of plastics. In this regard, six (TGA) and tensile tests were performed and case materials assessed included two (PET), two (PP), and two (PE) in their virgin and recycled forms.

The samples were sorted, cleaned, shredded into flakes, and then extruded. So, according to the manufacturer, the samples were processed with the same conditions used for the virgin counterparts. However, additives such as plasticizers and fillers were added in order to increase the thermomechanical properties of the materials, among others.

The TGA curves obtained were similar no matter the origin of the plastic, although a residue of 5% was found in some recyclates—in all except for PET.

Relative to the mechanical properties, the elongation, Young modulus, and ultimate tensile strength for the three polymers PET, PP, and PE were analyzed. In the case of PET, the recyclates showed greater ultimate tensile strength and elongation than the virgin plastics, showing, however, the same young modulus. For the other polymers, the virgin PP material showed better properties by 10% to 15% in all the parameters. Regarding PE, the recyclate had a greater elongation by 5%, and the other properties of the virgin PP were about 35% above the recyclates.

The studies showed a good overall performance of the recycled material thermally and mechanically, which makes the recycled polymers a good replacement for the virgin polymers.