▎ 摘　　要

NOVELTY - The high transparent cellulose acetate biodegradable composite film has upper and lower three layers of film. The upper layer film is cellulose acetate film. The middle layer film is made of polyurethane adhesive. The lower layer film is composed of 80-80 wt.% polybutylene adipate terephthalate and 20-25 wt.% biological starch. USE - High transparent cellulose acetate biodegradable composite film useful as food packaging material. ADVANTAGE - The cellulose acetate biodegradable composite film has high transparency, good bacteriostatic properties, high gas barrier properties and high mechanical properties. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a preparation method of the high transparent cellulose acetate biodegradable composite film, which involves: dissolving the cellulose acetate, preparing into 8-20 wt.%, cellulose acetate solution, adding rare earth doped nano titanium dioxide and plasticizer, mixing uniformly, de-foaming to obtain casting solution; dissolving the polystyrene to prepare polystyrene solution with mass fraction of 14-26 wt.%, coating the casting film liquid on the template by casting method, thermally curing to form an intermediate film, stripping the obtained intermediate film and the template, coating the polystyrene solution on one side of the intermediate film, drying, obtaining the upper layer film; mixing the polybutylene adipate terephthalate and biological starch, and extruding master batch, where the master batch is made into lower layer film by blowing film; mixing 0.2-0.3 pts. wt. cellulose, 3.8-4.7 pts. wt. ionic liquid and 5-7 pts. wt. chitosan acetic acid solution to form a casting liquid, casting film on the lower layer film, drying, forming a barrier reinforcing film on the lower layer film; and roller coating polyurethane adhesive on the barrier reinforcing film, pressing one side of the upper layer film not sprayed with the polystyrene solution with the polyurethane adhesive and curing.