▎ 摘　　要

NOVELTY - Preparation method of polylactic acid gas barrier composite membrane involves (i) dissolving polylactic acid in solvent, adding amino-functionalized graphene oxide, using ultrasonic vibration for 30 minutes to obtain a mixture, pouring in a flat mold, and volatilizing the solvent to obtain an amino-functionalized graphene oxide/polylactic acid composite film, (ii) spraying chloroform dispersion of ethylenediamine and chloroform dispersion of graphene oxide on the surface of the composite film to obtain ethylenediamine/graphene oxide coating on surface of composite film, and (iii) subjecting the modified composite film to hot-pressing treatment, and converting the graphene oxide sheet layer on the surface into a thermally reduced graphene sheet layer to obtain the product. USE - The method is used for preparing polylactic acid gas barrier composite membrane. ADVANTAGE - The composite membrane has a relatively high barrier ability to water vapor and oxygen, meets the packaging material field with high gas barrier requirement, and has a wide range of industrial use value.