Dynamic Rheology and Microstructure of Polypropylene/Clay Nanocomposites Prepared Under Sc-CO2 by Melt Compounding
Dynamic Rheology and Microstructure of Polypropylene/Clay Nanocomposites Prepared Under Sc-CO2 by Melt Compounding
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DOI：
10.1115/imece2007-43352
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发表时间：
2008-02
影响因子：
6.6
通讯作者：
Yang Zhao;Hanxiong Huang
中科院分区：
文献类型：
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作者：
Yang Zhao;Hanxiong Huang
采用超临界CO2（Sc-CO2）作为辅助气体，利用双螺杆挤出机制备了聚丙烯（PP）/粘土纳米复合材料。使用流变仪在振荡模式下测量动态流变性能。采用X射线衍射和透射电子显微镜对挤出纳米复合材料的微观结构进行了表征。结果表明，存在一个最佳的CO2浓度。当CO2浓度增加到最佳水平时，纳米复合材料倾向于更粘稠，特别是在低频下。而进一步增加CO2浓度则导致复合粘度和动态模量的降低。当Sc-CO2浓度不高于优化水平时，有助于提高纳米粘土在PP基体中的分散程度，过量的CO2会对粘土的分散产生负面影响。Copyright © 2007 by ASME
The polypropylene (PP)/clay nanocomposites were prepared using a twin screw extruder with the aid of the supercritical carbon dioxide (Sc-CO2 ). The dynamic rheological properties were measured using a rheometer in the oscillatory mode. X-ray diffraction and transmission electron microscopy were used to characterize the microstructure of extruded nanocomposites. Results showed that an optimized CO2 concentration existed. When the CO2 concentration increased up to the optimized level, the nanocomposites tended to be more viscous, especially at low frequency. Whereas further increasing the CO2 concentration resulted in the decrease in the complex viscosity and dynamic moduli. The presence of Sc-CO2 with the concentration not higher than the optimized level was helpful to promote the degree of dispersion of the nano-clay in PP matrix, and overloaded CO2 would have negative effect on the clay dispersion.Copyright © 2007 by ASME