| Starch-based biodegradable plastics is a kind of important degradable polymer material. In this paper, improving the mechanical properties and water-resistance of the material was focused on, ensuring its biodegradability at the same time. And the change of melt flow index was analyzed. In the end, biodegradability was measured roughly and film was blowed.Firstly, the mechanical properties of three different thermoplastic starches made from edible starch, industrial starch and cassava starch were compared and the influence of the glycerol content on the properties of each system was analyzed. Secondly, starch was blended with polyvinyl alcohol by single screw extruder with water and glycerol as plasticizers. The influence of the contents of PVA and glycerol on the mechanical property and water-resistance of the material was also analyzed. Thirdly, thermoplastic starch was prepared through single screw extruder with water and glycerol as plasticizers, which was then blended with polycaprolactone with the molecular weight of 50 000 by single screw extruder. Then the influence of the contents of different constituents on the mechanical properties, water-resistance and melt flow index was studied. Finally, glycerol as a plasticizer was added into starch with equilibrium moisture content of 12%. And thermoplastic starch was prepared by double screw extruder. Then it was blended with polycaprolactone with different molecular weight and ethylene-vinyl alcohol copolymer by single screw extruder. Then similar studies on the factors of the properties of the blends were conducted. In addition, the lubrication and method of making TPS/EVOH blends from master batch were studied. Finally, the biodegradability of some samples of TPS/EVOH and TPS/PCL blends were measured roughly by indoor soil burial method and film was tried to blow with TPS/PCL blends in the ratio 60:40 and 50:50.
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