THERMAL AND THERMOMECHANICAL BEHAVIOUR OF INJECTION MOLDED SOLID AND MICROCELLULAR POLYLACTIC ACID (PLA) /POLYHYDROXYBUTYRATE-VALERATE (PHBV) BLENDS

摘要

This paper investigated the thermal and dynamic mechanical properties of solid and microcellular injection molded polylactic acid (PLA)/polyhydroxybutyrate-valerate (PHBV) blends of different weight ratios. Nitrogen (N_2) in a supercritical state was used as the physical blowing agent for molding microcellular PLA/PHBV tensile test bars. The thermal and thermodynamic properties of the blends were characterized by differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). The results showed that when the content of PHBV exceeded 45% it could significantly affect the crystallinity of the PHBV and improve the storage modulus for both solid and microcellular components. It was also found that the glass transition temperature, T_g, of the PLA phase decreased with increasing PHBV content.