Recycling of a commercial biodegradable polymer blend: Influence of reprocessing cycles on rheological and thermo-mechanical properties

Mechanical recycling is a viable option for reducing plastic waste, especially for post-consumer waste and scraps from production processes. Biodegradable polymers have gained attention as alternatives to conventional ones, and their potential for reprocessing using standard techniques before composting needs to be explored. This study focused on a commercial biodegradable polymer blend which underwent ten extrusion cycles to assess the effects of mechanical recycling on mechanical properties, rheological behavior, and thermal stability. The results indicated that the blend's mechanical properties were largely maintained across the extrusion cycles, with only a 53 % decrease in ductility. The thermal stability slightly declined by 2.3 % in T5% onset temperature. This can be attributed to a balance between molecular chain scission (resulting in an average molecular weight reduction of approximately 8.4 %) and crosslinking phenomenon (evidenced by an increase in complex viscosity throughout the extrusion cycles). Overall, the results suggest a suitable recycling attitude of this material.