不同结构聚苯乙烯/蒙脱土复合材料的熔体流动行为研究

分别将聚苯乙烯树脂(PS)与钠基蒙脱土(Na-MMT)和有机化蒙脱土(OMMT)通过熔融复合制备纳米黏土改性的复合材料。通过X射线衍射(XRD)对复合材料的微观结构进行了分析,采用HAAKE流变仪和熔体流动速率仪研究了复合材料的熔体流动行为。结果表明,Na-MMT在与PS熔融复合前后,其片层间距没有发生变化,PS分子链没有插入蒙脱土片层之间,所形成的是一种填充型复合材料。OMMT在熔融复合后,片层间距显著增大,与PS分子链形成了插层复合结构。蒙脱土含量相同时,PS/Na-MMT复合体系的熔体流动性能比PS/OMMT体系更好。研究认为,熔融复合过程中PS分子链的断链和2种复合材料结构上的差异是影响2种材料流动性能的主要因素。

Melt Rheological Behavior of PS/MMT Composites With Different Structures

The composites of PS/Na-MMT and PS/OMMT were prepared by melt-blending PS resin with Na-MMT and OMMT, respectively. The microstructures of the composites were characterized by X-ray diffraction (XRD), and the melt flow behavior of the composites was studied by HAAKE rheometer and melt flowing rheometer. The result shows that the interlayer space of Na-MMT remains constant, PS molecular chains did not insert between lamella of MMT, PS/Na-MMT composite is simple filled composite. But the lamellar distance of OMMT increases obviously after the melt-blending process, indicating that an intercalated structure is formed in PS/OMMT composites. The PS/Na-MMT composite possesses better rheological behavior than PS/OMMT composite under the same MMT content condition. It is considered that the scission of PS chains and the structural difference between the two composites are the main factors affecting the rheological behavior of the two composites.