Technological watch

Disclosed is a multilayer biodegradable film, composed of a surface layer, a core layer, and an inner layer. The components of the core layer and the ratios thereof are: 100 parts of PVA, 60-100 parts of starch, 30-42 parts of a plasticizer, 0.4-1.0 part of a chemical modifier, and 0.2-0.6 part of a chain extender; the components of the surface layer and the inner layer and the ratios thereof are: 100 parts of PBAT, 30-50 parts of PHA, and 1-3 parts of a lubricant. Also disclosed is a preparation method for the multilayer biodegradable film. According to the multilayer biodegradable film prepared in the present invention, a film having good water-barrier properties is attached to each of the inner and outer surfaces of a PVA/starch film having good air tightness, so that a resulting film is good in both air tightness and waterproofness; moreover, the multilayer biodegradable film is completely biodegradable, is environmentally friendly, and is particularly suitable for food packaging.