Poly(lactic acid)/Poly(butylene adipate-co-terephthalate) films with simultaneous high oxygen barrier and fast degradation properties

Although poly （lactic acid）(PLA) is a good environmentally-friendly bio-degradable polymer which is used to substitute traditional petrochemical-based polymer packaging films,the barrier properties of PLA films are still insufficient for high-barrier packaging applications.In this study,oxygen scavenger hydroxyl-terminated polybutadiene （HTPB） and cobalt salt catalyst were incorporated into the PLA/poly （butylene adipate-co-terephthalate）(PLA/PBAT),followed by melting extrusion and three-layer co-extrusion blown film process to prepare the composite films.The oxygen permeability coefficient of the composite film combined with 6 wt%oxygen scavenger and 0.4 wt%catalyst was decreased significantly from 377.00 cc·mil·m-2·day-1·0.1 MPa-1to 0.98 cc·mil·m-2·day-1·0.1 MPa-1,showing a remarkable enhancement of 384.69times compared with the PLA/PBAT composite film.Meanwhile,the degradation behavior of the composite film was also accelerated,exhibiting a mass loss of nearly 60%of the original mass after seven days of degradation in an alkaline environment,whereas PLA/PBAT composite film only showed a mass loss of 32%.This work has successfully prepared PLA/PBAT composite films with simultaneously improved oxygen barrier property and degradation behavior,which has great potential for high-demanding green chemistry packaging industries,including food,agricultural,and military packaging.