Abstract: Polypropylene/halloysite nanotubes(PP/HNTs)nanocomposites with 33 phr HNTs were prepared by melt mixing using a co-rotating twin-screw extruder.PP/HNTs nanocomposite samples were taken from three positions along the extruder and from the die exit.Microstructure,rheological properties,and thermal stability of the nanocomposite samples were analyzed.The results showed that the sizes of aggregates of the HNTs rapidly decreased and the HNTs were dispersed more and more uniformly in the PP matrix due to the dispersive and distributive mixing provided by the screw configuration arranged in this work.As a result,the storage modulus and relaxation time at low frequency for the nanocomposite samples taken from three positions along the extruder increased gradually,whereas their terminal slopes decreased gradually.The thermal stability of the PP/HNTs nanocomposite sample taken from die inlet was better than that taken from die exit due to higher effectiveness of the entrapment of decomposition products into the nanotube lumens of more unoriented HNTs in the former sample.

Key words: halloysite nanotubes, polypropylene, nanocomposites, microstructure, rheological property, thermal stability

摘要： 采用双螺杆挤出机制备聚丙烯(PP)基高含量(33 phr)埃洛石纳米管(HNTs)复合材料,从挤出机沿程3个位置和机头出口处取样,观察样品的微观结构并测试其流变性能和热稳定性。结果表明,本文设置的螺杆结构提供的分散和分布混炼使PP/HNTs复合材料中HNTs团聚体的尺寸快速减小,HNTs在PP基体中分散得越来越均匀,使挤出机沿程3个位置所取复合材料样品的低频区储能模量逐渐提高、末端斜率逐渐降低、松弛时间逐渐变长。机头入口所取复合材料样品的热稳定性要比机头出口样品的高,这归因于前者样品中较为无序且较均匀排列的HNTs纳米空腔能更有效地诱捕降解产物。

关键词: 埃洛石纳米管, 聚丙烯, 纳米复合材料, 微观结构, 流变性能, 热稳定性