甘油增塑热塑性淀粉的流变相变性质

Rheological and Phase Transition Properties of Thermoplastic Starch Under the Plasticization of Glycerol

流变性质和相变性质是指导热塑性淀粉(TPS)生产加工的重要参数。文中利用转矩流变仪(密炼机)和差示扫描量热法(DSC)研究甘油增塑淀粉时TPS流变相变性质的变化。结果表明,甘油增塑时,对淀粉流变性能的影响与水不同;由于转子扭矩的变化主要由TPS相变产生,而甘油的润滑效应不利于淀粉塑化,因此TPS的塑化程度随着甘油含量的增多先减小后增大;升高转子转速会加大剪切力,加剧相变;同样初始温度越高,相变越容易发生,且温度对相变程度的影响显著于转速。

Rheological and phase transition properties are the important parameters for industrial production of thermoplastic starch（TPS）.In this paper,Haake Rheometer and differential scanning calorimetry（DSC） were used to study TPS′s rheological and phase transition properties under the plasticization of glycerol.The results show that： the plasticization effect of glycerol is different from that of water.On one hand,the change of torque is caused by the phase transition of starch;On the other hand,it is caused by the material feeding of glycerol which can lubricate starch while goes against the plasticization of starch.Consequently,with the increase of glycerol,the plasticization degree of TPS decreases firstly,but increases later.What＇s more,the high roller speed can enhance shear force,so can intensify the plasticization degree of TPS.Similarly,the high temperature can also accelerate the plasticization of TPS,which is even more notably.