Processing and Mechanical Properties of Plasticized Starch by Different Plasticization Methods

The thermoplastic processing and mechanical properties of starch were investigated by different plasticization methods. Glycerol was chosen as the plasticizer for starch. The effect of glycerol with different amount was studied. The two plasticizing methods of direct adding and high-speed mixing of glycerol were used to plasticize starch, respectively. The results showed that the suitable processing temperatures ranged from 105°C to 140°C. The tensile strength of the obtained thermoplastic starch decreased and the breaking elongation ratio increased with the increase of glycerol content. When the percent of glycerol was 30%, the extrudate of platicized starch has excellent liquidity and the appearance of the extrudate was smooth. Compared with the plasticizing method of direct adding, the plasticization method of high-speed mixing is more beneficial to plasticize starch.