▎ 摘　　要

NOVELTY - The preparation method of high water resistant polyvinyl alcohol/nanocrystalline cellulose/graphene oxide composite film involves mixing nanocrystalline cellulose aqueous dispersion and graphene oxide aqueous dispersion, ultrasonically dispersing, dissolving polyvinyl alcohol, heating, cooling, adding nanocrystalline cellulose and graphene oxide suspension to obtain polyvinyl alcohol/nanocrystalline cellulose/graphene oxide mixed solution, leaving still the mixed solution, defoaming, cast molding in a glass mold, leaving still, and drying. USE - Preparation method of high water resistant polyvinyl alcohol/nanocrystalline cellulose/graphene oxide composite film for biodegradable packaging material. ADVANTAGE - The method enables preparation of polyvinyl alcohol/nanocrystalline cellulose/graphene oxide composite film with excellent water resistance and mechanical properties. DETAILED DESCRIPTION - The preparation method of high water resistant polyvinyl alcohol/nanocrystalline cellulose/graphene oxide composite film involves (1) preparing nanocrystalline cellulose aqueous dispersion by dispersing 1 g nanocrystalline cellulose in 200 ml deionized water, preparing into a solution with 0.005 g/ml nanocrystalline cellulose solution, adding to 100 W ultrasonic cleaning machine, and ultrasonically dispersing for 30 minutes, (2) preparing graphene oxide aqueous dispersion by dispersing 1 g graphene oxide in 200 ml deionized water, preparing into a solution with 0.005 g/ml graphene oxide solution, adding into 100 W ultrasonic cleaning machine, and ultrasonically dispersing for 30 minutes, (3) preparing nanocrystalline cellulose and graphene oxide composite aqueous dispersion by mixing nanocrystalline cellulose aqueous dispersion and graphene oxide aqueous dispersion according to mass ratio of 1:2, 1:1, and 2:1, stirring at room temperature for 10 minutes, where the concentration of nanocrystalline cellulose and graphene oxide is 0.005 g/ml, adding to 100 W ultrasonic cleaning machine, and ultrasonically dispersing for 30 minutes, (4) preparing polyvinyl alcohol/nanocrystalline cellulose/graphene oxide mixed solution by dissolving 1 g polyvinyl alcohol in 10 ml deionized water, heating and stirring at 90 degrees C for 60 minutes in a magnetic heating stirrer, cooling to room temperature, adding 2-10 ml nanocrystalline cellulose and graphene oxide suspension, and stirring at room temperature for 30 minutes, where the mass ratio of nanocrystalline cellulose and graphene oxide composite nanoparticles and polyvinyl alcohol is 1-5%, and (5) leaving still the polyvinyl alcohol/nanocrystalline cellulose/graphene oxide mixed solution prepared in the step (4) at room temperature for 2 hours, defoaming, cast molding in a glass mold, leaving still for 24-36 hours at room temperature, and drying at 40 degrees C for 4 hours to obtain film with thickness of about 50 microns.