Flexural properties of polystyrene/organo-montmorillonite masterbatch composites

In this study, a montmorillonite masterbatch (OMMT-MB) containing polystyrene and organo-montmorillonite was first prepared by extrusion processes. Subsequently, blending of polystyrene (PS) and montmorillonite masterbatch (OMMT-MB) was performed by the direct melt intercalation method using a twin-screw extruder followed by compression molding. The flexural and morphological properties of PS/OMMT-MB were characterized by flexural tests and field-emission scanning electron microscopy (FESEM). The flexural tests were carried out at two different testing speeds, i.e. 5 mm/min and 50 mm/min. The flexural modulus of PS increased significantly with the addition of OMMT. This is due to the reinforcement and stiffness of the OMMT-layered silicates. It is interesting to note that the flexural modulus of PS/OMMT-MB was higher than that of both PS and montmorillonite masterbatch (OMMT-MB). This indicates that the dispersion of OMMT in the PS was better and more homogeneous by using the montmorillonite masterbatch approach.