Abstract:

The model and numerical simulation of three-dimensional non-isothermal for sol-gel reaction process of preparing PP/TiO₂ nanocomposites between mixing and reaction process in twin screw extruder were established by POLYFLOW software with the finite element method. The effects of screw speed, screw pitch and precursor concentration on the preparation of PP/TiO₂ nanocomposites reaction process about mixing efficiency and reaction rate were analyzed. The results showed that the increasing pitch which enhanced the temperature of polymer and improved mixing efficiency in twin screw extruder contributes to the reaction process. The increasing screw speed and precursor concentration were not conducive to the reaction, because of the drop of the fractional conversion.

Key words: Numerical simulation, Mixing efficiency, Non-isothermal, Nanocomposites, Two screw extruder

摘要： 采用有限元法,利用POLYFLOW 软件,建立双螺杆挤出机输送段三维非等温模型,数值模拟了双螺杆挤出机输送段中通过溶胶-凝胶法制备聚丙烯/二氧化钛(PP/TiO2)纳米复合材料的反应过程,分析了螺杆转速、螺距、前驱体质量分数等控制条件对PP/TiO2纳米复合材料的混合效率及反应速率的影响。结果表明,随着螺杆螺距的增加,挤出机内物料温度逐渐升高,混合效率逐渐增大,平均转化率也逐渐升高;增加转速和前躯体质量分数,平均转化率降低,不利于反应的进行。

关键词: 数值模拟, 混合效率, 非等温, 纳米复合材料, 双螺杆挤出机