▎ 摘　　要

NOVELTY - Multi-layer high-barrier high-strength biodegradable film comprises upper surface layer, central layer and lower surface layer stacked in sequence, where the upper surface layer and lower surface layer includes polybutylene adipate terephthalate pellets, polymer D-lactic acid pellets, modified gas barrier agent, chain extenders, antioxidants and compatibilizers, and the central layer includes polybutylene adipate terephthalate pellets, polymer L-lactic acid pellets, chain extender, antioxidant and compatibilizer. USE - Used as multi-layer high-barrier high-strength biodegradable film. ADVANTAGE - The preparation method: has simple process, short process, low cost and improved production efficiency. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of multi-layer high-barrier, high-strength biodegradable film, comprising (1) placing epoxy silane coupling agent in a mixed solvent of ethanol and water to obtain mixed solution, (2) dispersing gas barrier agent in the mixed solution, stirring and reacting for 5-6 hours to obtain precipitate, taking out precipitate, drying at 100-110 ℃ to obtain modified gas barrier agent, (3) ultrasonically dispersing the modified gas barrier agent in solution of polymer D-lactic acid pellets and dimethyl sulfoxide, adding N,N-dimethylbenzylamine as a catalyst, reacting at high temperature, centrifuging and washing with dichloromethane and ethanol to obtain reaction mixture, (4) melting and blending the reaction mixture with polybutylene adipate terephthalate, chain extender, antioxidant, and compatibilizer in an extruder to obtain raw materials for upper and lower surface layers, (5) evenly mixing polybutylene adipate terephthalate, polymer L-lactic acid pellets, chain extender, antioxidant and compatibilizer, which is the raw material of the center layer, and (6) placing the raw materials of upper surface layer, central layer and lower surface layer into two different screw extruders, carry out plasticization at 160-190 ℃, extruding the three strands of materials through a co-extrusion molding machine, rolling, cooling, pulling, and shearing in sequence to obtain final product.