Expanded polystyrene (EPS) is a commonly used polymer in the packaging industry. The great importance of EPS recovery is related to the material's short service life and the high volume of EPS waste. The aim of the present work was to reduce the volume of waste by its mechanical milling and crushing and subsequent reintroduction into mass production. The results of thermal and infrared analysis indicate that the material does not degrade during the recovery process; indeed, the thermal properties of the recycled material are even better than those of the virgin product. Tensile tests showed that the recycled and virgin materials have similar mechanical behaviour. From the results obtained we can conclude that recycled polystyrene can replace virgin polystyrene in some industrial processing, thus reducing the cost of the final product.

Poly(lactic acid) (PLA) was plasticized with maleinized linseed oil (MLO) and further reinforced with sheep wool fibers recovered from the dairy industry. The wool fibers were firstly functionalized with 1 and 2.5 phr of tris(2-methoxyethoxy)(vinyl) (TVS) silane coupling agent and were further used in 1, 5, and 10 phr to reinforce the PLA/MLO matrix. Then, the composite materials were processed by extrusion, followed by injection-molding processes. The mechanical, thermal, microstructural, and surface properties were assessed. While the addition of untreated wool fibers to the plasticized PLA/MLO matrix caused a general decrease in the mechanical properties, the TVS treatment was able to slightly compensate for such mechanical losses. Additionally, a shift in cold crystallization and a decrease in the degree of crystallization were observed due to the fiber silane modification. The microstructural analysis confirmed enhanced interaction between silane-modified fibers and the polymeric matrix. The inclusion of the fiber into the PLA/MLO matrix made the obtained material more hydrophobic, while the yellowish color of the material increased with the fiber content.