▎ 摘　　要

NOVELTY - High-barrier antibacterial nano-silver-graphene modified polylactic acid comprises nano-silver loaded amino functionalized graphene and succinic anhydride grafted polylactic acid in a ratio of 0.5-4:100. USE - High-barrier antibacterial nano-silver-graphene modified polylactic acid. ADVANTAGE - The high-barrier antibacterial nano-silver-graphene modified polylactic acid improves the barrier property of polylactic acid packaging material to air and moisture and enhances the inhibiting ability of microorganism such as bacteriaor fungi. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method for preparing a high-barrier antibacterial nano-silver-graphene modified polylactic acid, which involves: (A) adding graphene oxide to distilled water, placing in an ultrasonic device, perform ultrasonic dispersion treatment, adding ammonia water to adjust the pH of the solution to 9-11, adding triethylenetetramine, heating to 70-90 degrees C in a nitrogen atmosphere, reacting for 2-4 hours, centrifuging, washing and drying to prepare amino functionalized graphene; (B) adding amino-functionalized graphene to distilled water solvent, adding polyvinylpyrrolidone and silver nitrate after uniform ultrasonic dispersion, stirring for 2-6 hours under dark conditions, then adding sodium citrate, heating to 90-110 degrees C to avoid light stirring and refluxing reaction for 1-3 hours, filtering, washing and drying to prepare nano-silver-loaded amino-functionalized graphene; (C) adding DL-lactide, maleic anhydride and dibenzoyl peroxide to the acetone solvent, heating to 100-120 degrees C, stirring and refluxing at a constant speed for 1-2 hours, placing the solution in an ice-water bath, adding tetrahydrofuran to dissolve, adding distilled water until a large amount of precipitation is precipitated, filtering to remove the solvent, washing the solid product with distilled water and ether and drying to prepare succinic anhydride grafted polylactic acid; and (D) adding tetrahydrofuran solvent and nano-silver-loaded amino-functionalized graphene into the reaction flask, adding succinic anhydride grafted polylactic acid after uniform ultrasonic dispersion, stirring at 5-20 degrees C for 1-3 hours, pouring the solution into the film forming mold, naturally casting, removing solvent by drying to prepare high-barrier antibacterial nano-silver-graphene modified polylactic acid.