Mechanical, thermal and degradation properties of poly(d,l-lactide)/poly(hydroxybutyrate-co-hydroxyvalerate)/poly(ethylene glycol) blend

The mechanical, thermal and biodegradable properties of poly(d,l-lactide) (PDLLA), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and poly(ethylene glycol) (PEG) blends were studied. The influence of PEG on the tensile and impact strengths of the blends was investigated. The results showed that the toughness and elongation at break of the PDLLA/PHBV (70/30) blends were greatly improved by the addition of PEG, and the notched Izod impact strength increased about 400% and the elongation at break increased from 2.1% to 237.0%. The thermal and degradation properties of the blends were investigated by differential scanning calorimeter (DSC) and thermogravimetric analyzer (TGA), it was found that the thermal stability of PHBV in the presence of PDLLA was improved. The degradation test showed that the addition of PEG could notably accelerate the biodegradation of the blends in the soil at room temperature, and the mass loss is about 20% after 30 days of the storage.