The influence of D-lactide content, high-temperature drawing, and blending with poly(butylene adipate-co-terephthalate) elastomer on the physical aging kinetics and ductility of poly(lactic acid)

In this paper, we investigated the effect of D-lactide content, high-temperature drawing, and blending with poly(butylene adipate-co-terephthalate) (PBAT) on the physical aging kinetics of poly(lactic acid) (PLA), and its morphology, mechanical properties, and phase structure. As PLA is only tough for 1 or 2 h after processing, or after being heated above the glass transition temperature and back, it is crucial to know how we can avoid, or at least slow down, the kinetics of physical aging. Toughening elastomers, in this case, PBAT, can also influence this. PBAT also works as a nucleating agent and so it slows down physical aging; therefore, it toughens PLA not only through increasing its elongation at break and inhibiting crack propagation. We also investigated the influence of the phase structure of the blend on ductility, with a ball-burst test and a scanning electron microscopy (SEM).