Mechanical Properties of Polystyrene-Montmorillonite Nanocomposites-Prepared by Melt Intercalation

A series of polymer-clay nanocomposite (PCN) materials, consisting of thermoplastic polystyrene (PS) sample and dispersing inorganic organoclay platelets, were successfully prepared. First, organoclay was prepared by performing cationic exchange reactions between the sodium ions existing in the interlayer region of the clay mineral and intercalation agent, followed by dispersing the organophilic clay into a PS basis through the melt intercalation approach performed by a twin-screw mixing method. The as-prepared PCN materials in the form of a pellet subsequently characterized using the powder X-ray diffraction (XRD) and the transmission electron microscopy (TEM). In this study, it is found that the wear resistance of PS to be effectively enhanced by the incorporation of low loading organophilic clay platelets. The surface morphological image for the neat PS and PS-clay after a wear resistance test has also been compared and identified by the scanning electron microscopy (SEM). Furthermore, the effect of organoclay on three other different measurement types of mechanical properties for as-prepared PCN materials, e.g., flexural tests, impact tests, and micron-nano indenter tests were performed and compared. Generally, PCN materials exhibited an obvious enhancement of mechanical properties of neat polymer by an incorporated low loading of organophilic clay platelets into a polystyrene matrix used for the evaluation of mechanical properties as-prepared samples. For example, mechanical strength (excepting flexural strength) almost remain same beyond 3 wt % clay loading in PS, whereas much detrimental effect being observed in the wear loss in case of PCNs with 5 wt % clay than 3 wt %. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 115:288-296, 2010