The invention provides a
polylactic acid (PLA) / poly(butylene succinate-butylene
adipate) (PBSA) blown film and a preparation method thereof. The blown film comprises a mixture of PLA, PBSA,
plasticizer diethylene glycol monobutyl
ether adipate, a
lubricant, a plastic
lubricant and an
antioxidant. The PLA, the PBSA, the
lubricant, the plastic lubricant and the
antioxidant are first mechanically mixed into a premix, the premix is added through a feeding port of a twin-screw extruder, meanwhile the
plasticizer diethylene glycol monobutyl
ether adipate is metered and added in through a liquid feeding port of the twin-screw extruder, modified
polylactic acid blown film special resin is prepared by melt-extruding, water-cooling,
pelletizing and
drying, the modified
polylactic acid blown film special resin is blown by a
film blowing machine to form a transparent tear-resistant biodegradable film. The PBSA, the plasticizers, the lubricant, the plastic lubricant and the
antioxidant can effectively increase the tensile elongation at break and tear strength of polylactic acid films, maintains the transparency of the polylactic acid, and solves the
brittleness defects of the polylactic acid films. The polylactic acid (PLA) / poly(butylene succinate-butylene adipate) (PBSA) blown film has good mechanical properties and excellent transparency, and can replace PE, PP, PVC and the like for preparation of films and sheets.