Abstract
This research aims to formulate biobased and biodegradable packaging films with high toughness and fast home-compost biodegradation using ternary blends of polylactic acid (PLA), Para rubber (NR), and thermoplastic starch (TPS) through blown-film extrusion. The TPS content in this work ranges from 5 to 20 wt%, while the PLA: NR ratio is fixed at 70:30. At this PLA: NR ratio, the blend with 10 wt% TPS (PNT10) exhibited the highest % elongation at break and tensile toughness. Peroxide radical initiator was investigated as a potential additive for improving the properties of the ternary blend. Our binary interaction study indicated that peroxide initiated grafting reactions of PLA-NR and NR-TPS pairs, while no grafting occurred between PLA and TPS. In ternary blends, the highest peroxide content (0.5 wt%) increased the % elongation at break up to 120%, with the tensile toughness reaching 7255 MJ/m(3). The improved compatibility induced by peroxide addition was supported by enhanced dispersion of TPS in the PLA/NR matrices. Results from the room-temperature soil burial test indicated that the presence of TPS could significantly accelerate the home-compost degradation of PNT films compared to films produced from neat PLA and PLA/NR. This suggests its potential as both a cost reducer and a biodegradation accelerator.