Biodegradation of poly-e-caprolactone/poly-beta-hydroxybutyrate blend.

Poly-E-caprolactone (PCL), poly-beta-hydroxybutyrate (PHB) and one of their blends have been incubated in presence of some microbial consortia isolated from plastic-contaminated environments. In the conditions used in this work, both pure PCL and PHB samples were degraded with strong erosion of the amorphous zones. The PCL/PHB 70/30 blend showed, after only 20 days of incubation, that spheres of PCL were bordering with spherulites of PHB indicating complete degradation. The crystallinity content of homopolymers and blend were investigated at different degradation times: whilst PCL crystallinity remains constant, both PHB and the blend PHB-phase crystallinity increased. Data from differential scanning calorimetry are well fitted with those obtained by scanning electron microscopy, gel permeation chromatography and weight loss analysis.