Microstructure of Nanocomposites of Styrenic Polymers

Abstract

AbstractNanocomposites of three different styrenic polymers (polystyrene – PS, styrene‐butadiene‐styrene triblock copolymer – SBS, and styrene‐ethylene/butylene‐styrene triblock copolymer – SEBS) containing organophilic silicates have been prepared using three different techniques. The materials were prepared by melt mixing, solution casting and a process in which a highly filled masterbatch prepared by solution is mixed in the melt with the pure polymer. These composites were characterized by X‐ray diffraction (XRD), optical microscopy (OM), transmission electron microscopy (TEM) and small amplitude oscillatory shear analysis (SAOS). The results obtained showed that the nanocomposites of PS formed an intercalated microstructure, while those of SBS and especially SEBS are more easily exfoliated. To achieve this better silicate dispersion it was shown that it is necessary to use solution casting as one of the stages in the nanocomposite preparation. The masterbatch process showed to be an effective method to disperse the clay because it combines the advantages of the solution casting technique, which is good to dissolve coarse clay aggregates, and the shear provided by melt mixing.