Toward the Decarbonization of Plastic: Monopolymer Blend of Virgin and Recycled Bio-Based, Biodegradable Polymer

Decarbonization of plastics is based on two main pillars: bio-based polymers and recycling. Mechanical recycling of biodegradable polymers could improve the social, economic and environmental impact of the use of these materials. In this regard, the aim of this study was to investigate whether concentrations of the same recycled biopolymer could significantly affect the rheological and mechanical properties of biodegradable monopolymer blends. Monopolymer blends are blends made of the same polymers, virgin and recycled. A sample of commercially available biodegradable blend was reprocessed in a single-screw extruder until two extrusion cycles were completed. These samples were exposed to grinding and melt reprocessed with 75% and 90% of the same virgin polymer. The blends were characterized by tensile tests and rheological tests. The results obtained showed that while multiple extrusions affected the mechanical and rheological properties of the polymer, the concentration of the reprocessed material present in the blends only very slightly affected the properties of the virgin material. In addition, the experimentally observed trends were accurately predicted by the additive model adopted.