分提棕榈油的相容性及非等温结晶性质对以其为基料油的塑性油脂品质有重要影响.为更好地应用分提棕榈油,文中通过脉冲核磁共振仪及等温结晶曲线研究了棕榈硬脂(44℃)与棕榈软脂(24℃)的相容性,并采用差式扫描量热仪对二者按一定比例混合得到的复配体系的非等温结晶行为进行研究.实验表明:二者整体上相容性较好,当棕榈硬脂比例高于50%及温度高于33.3℃时存在轻微共晶现象;非等温结晶过程中,在同一降温速率下,随着棕榈硬脂比例的增加,结晶峰变宽,峰值温度逐渐升高,在棕榈硬脂含量相同时,随降温速率的升高结晶峰焓变增大.
The compatibility and non-isothermal crystallization of fractionated palm oil greatly affect the quality of fractionated palm oil-based plastic oils. For better application of fractionated palm oil,the compatibility of the blends of palm stearin (44℃)and palmitin (24℃)was studied by means of pulsed nuclear magnetic resonance and isothermal crystallization curves,and the non-isothermal crystallization behavior of the blends was investigated via differential scanning calorimetry. The results show that the binary system of palm stearin and palmitin is of good compatibility and forms a eutectic mixture only when the palm stearin proportion and the temperature are respectively higher than 50% and 33. 3℃. Moreover,it is found that,during the non-isothermal crystallization of the blends,the exothermic peak broadens and the peak temperature increases with the palm stearin proportion at a constant cooling rate,and that the enthalpy variation increases with the cooling rate when the palm stearin proportion keeps constant.