▎ 摘　　要

NOVELTY - Preparation of preservative film involves providing acetone dispersion of copper oxide/graphene oxide composite nanomaterials with a concentration of 0.5-5 mg/mL, adding and dripping a dichloromethane solution of polylactic acid and the isopropanol dispersion of boron nanosheets to the acetone dispersion of copper oxide/graphene oxide composite nanomaterials, ultrasonically processing the water bath, adding ethylene dichloride and N-hydroxysuccinimide to the acetone dispersion of copper oxide/graphene oxide composite nanomaterials, transferring a mixed system to 60-80 degrees C in a protective gas atmosphere, stirring, reacting for 4-8 hours and drying to obtain composite nano-material modified polylactic acid, melt-kneading 100-200 pts. wt. composite nano-material modified polylactic acid, 15-40 pts. wt. starch, and 10-30 pts. wt. N-methylpyrrolidone, at a temperature of 175-195 degrees C to obtain a mixture (M1), transferring the mixture (M1) to a twin-screw extruder, extruding and granulating. USE - Preparation of preservative film (claimed). ADVANTAGE - The method enables preparation of preservative film having excellent hydrophilicity, flexibility, heat resistance, break elongation, antibacterial and preservative effect, water retention effect and moisturizing effect, shortens the degradation cycle, promotes the formation of a porous structure, and increased surface area. DETAILED DESCRIPTION - Preparation of preservative film involves providing acetone dispersion of copper oxide/graphene oxide composite nanomaterials with a concentration of 0.5-5 mg/mL, adding and dripping a dichloromethane solution of polylactic acid and the isopropanol dispersion of boron nanosheets to the acetone dispersion of copper oxide/graphene oxide composite nanomaterials while stirring, ultrasonically processing the water bath, adding ethylene dichloride and N-hydroxysuccinimide to the acetone dispersion of copper oxide/graphene oxide composite nanomaterials, transferring a mixed system to 60-80 degrees C in a protective gas atmosphere, stirring, reacting for 4-8 hours and drying to obtain composite nano-material modified polylactic acid, providing 100-200 pts. wt. composite nano-material modified polylactic acid, 15-40 pts. wt. starch, and 10-30 pts. wt., melt-kneading at a temperature of 175-195 degrees C for 10-30 minutes to obtain a mixture (M1), transferring the mixture (M1) to a twin-screw extruder at 175-185 degrees C, extruding and granulating. The mass ratio of the polylactic acid, copper oxide/graphene oxide composite nanomaterials, boron nanosheets, ethylene dichloride and N-hydroxysuccinimide is 100-200:10:1-5:1-5:0.2-1. The isopropanol dispersion of boron alkene nanosheets with a concentration of 0.05-0.5 mg/mL. The dichloromethane solution of polylactic acid with a concentration of 20-100 mg/mL.