Fortschritte im Recycling und Abfallmanagement

Mechanical Recyclability Potential of Biobased and Biodegradable Poly (Hydroxybutyrate)/Poly (Butylene Succinate-Co-Adipate) Blends

Abstract

Marwa Khemakhem*, Clara Le Rouzic, Thierry Falher, Valentin Thoury and Samira Ouardad El Bir*

The effect of repeated injection processing cycles on the structure and properties of poly (hydroxybutyrate)/ poly (butylene succinate-co-adipate) blends, initially extruded by using a twin screw extruder, was investigated. The recycling was simulated by performing five successive injections/ grinding runs. Neat poly (hydroxybutyrate) was also reprocessed under the same conditions as a reference. The results showed that the recyclability of PHB is restricted due to its sensitivity to thermomechanical degradation. Nevertheless, the PBSA addition had a stabilizing effect on PHB and an improved compatibility between the two components was observed during the reprocessing cycles due to a morphology evolution from cocontinuous to droplets in matrix type. This morphological transition was the main factor to the significant increase of the blend ductility right after the first injection cycle.

The thermal, the viscoelastic and the mechanical properties of this blend were maintained during the recycling process thus testifying that this formulation can be recycled several times by injection molding without losing its performances before being composted.