Study of injection molded microcellular polylactide (PLA)/poly(butylenes adipate-co-terephthalate) (PBAT) blends with various composition ratios

Foamed poly(lactide) (PLA)/poly(butylene adipate-co-terephthalate) (PBAT) blends were processed via the microcellular injection molding process using supercritical N₂ as a blowing agent. The effect of composition ratio on cell morphology, thermal properties, and mechanical properties of microcellular PLA/PBAT blends was investigated. Results showed that neat PLA presented a relatively small cell size and that the cell size became larger from the skin area to the central area of the sample. With increasing PBAT content (0-70 wt%), the cell size also increased, while the size distribution of the cells became uniform. In addition, the thermal properties of PLA, especially the glass transition temperature, Tg, were slightly affected by the addition of PBAT. The crystallization behavior of the PLA matrix was noticeably influenced. The PLA/PBAT blends showed decreased tensile strength and modulus, while the elongation was dramatically increased with increasing PBAT content.