Study on Structure-property Relationships of Polypropylene/OMMT Nanocomposites with Different Morphologies

Polypropylene (PP)/organophilic montmorillonite (OMMT) nanocomposites with three different morphologies have been identified as intercalated, partial intercalated and partial-exfoliated nanocomposites, respectively; which were prepared by controlling the processing conditions. The XRD analysis of nanocomposites determines the interlayer space inside OMMT in them; and the submicroscopic structure of three nanocomposites was observed by transmission electron microscopy (TEM) to distinguish the morphology of the nanocomposites. Furthermore, the melt fluidity, mechanical properties, melting and crystallization behaviour and thermal stability of nanocomposites were measured and analyzed. The melt flow rate (MFR) of partial- exfoliated nanocomposites decreased most; they had the most uniformly dispersed OMMT particles and the highest reinforcement of mechanical properties. The intercalated nanocomposites displayed the highest impact strength. The partial intercalated nanocomposites with good performance had the advantage of simple processing. The results showed that the dispersion morphology of OMMT in PP matrix determines the properties of nanocomposites, which means that the nanocomposites with different structures of OMMT dispersion would have specific properties. It is an achievement to develop polymer/OMMT nanocomposites with different performance capabilities by controlling the processing conditions.