(555f) Poly(L-lactic acid) Toughening

Poly(L-lactic acid) (PLA) is a biodegradable and bioabsorbable thermoplastic polyester derived from renewable resources like corn, starch, rice, etc. PLA has exhibited excellent biocompatibility and has been FDA approved. However, wide applicability of PLA in consumer and biomedical applications is limited by its poor toughness. This research focused on PLA toughening using biocompatible polymers like poly[(3-hydroxybutyrate)-co-(3-hydroxyhexanoate)] (PHBHHx) and poly(ethylene glycol) (PEG). PLA blends were processed using a twin screw microcompounder operated in co-rotating mode. The resultant blend films were characterized using tensile testing, differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXD), and dynamic mechanical analysis (DMA). The resultant blends had very low crystallinity, as characterized using DSC and WAXD analyses. Addition of a small amount (typically less than 20 wt%) of these additives to PLA significantly improved the toughness of the resultant blend.