• aging
• bio-based
• characterization
• compounding
• Polybutylene Adipate-co-Terephthalate (PBAT)
• recycle
• thermoplastic starch (TPS)

Conventional plastics’ persistent nature poses a serious environmental threat and is a major cause of plastic pollution globally. Traditional plastics can take centuries to decompose, accumulating in landfills, oceans, and ecosystems, where they seriously endanger human health, marine life, and animals. In response to this crisis, biopolymers offer a promising solution. Derived from renewable resources and designed to degrade naturally, biopolymers represent a more sustainable alternative to traditional plastics. Biodegradable polymers offer comparable performance to fossil-based polymers while significantly reducing environmental impact. By embracing biopolymers in packaging, manufacturing, and other applications, we can mitigate the detrimental effects of plastic pollution and move towards a more sustainable future.

Despite the advantages of using bio-based and biodegradable polymers, there are still obstacles when it comes to upscaling production and ensuring compatibility with current infrastructure. Achieving consistent mixing and dispersion of PBAT, TPS, and any additives throughout the compounded blend becomes increasingly challenging at larger scales. Poor compounding can result in variations in material characteristics and performance, impacting the quality of the end product. Another possible issue is a decrease in the properties of starch over time due to retrogradation, a process in which starch molecules reorganize and lose their functionality, potentially affecting the performance and durability of biopolymer products. Furthermore, the recyclability of PBAT/TPS blends is not well observed, which is a potential motivation for their widespread adoption.

This study focused on the evaluation of the potential industrial standpoint of the blending of two promising biodegradable polymers, Polybutylene Adipate-co-Terephthalate (PBAT) and thermoplastic starch (TPS) derived from potato starch with glycerol as a plasticiser. Considering factors such as the increase of screw speed during blending in a twin-screw extruder, the effect of reprocessing for four successive extrusion cycles, and storage time effects on the morphological, mechanical, and thermal properties of the blend. Blends with different processing rates were film-blown and injection-moulded. The resulting materials were characterized by using techniques such as TGA (Thermogravimetric Analysis), DSC (Differential Scanning Calorimetry), mixing index assessment, SEM (Scanning Electron Microscopy), tensile testing, and rotational rheometry. Following each processing step, the moisture content of the material was evaluated due to the water sensitivity of starch. The results provide insights into the feasibility and sustainability of PBAT-TPS blends for various applications in packaging and other industrial sectors.