The compatibilizing effect of polystyrene-based sodium methacrylate ionomer on the ionic content of ionomer/particle size/tensile properties relationship was studied for nylon-6/polystyrene blends. As the glass transition temperature of all kinds of blends showed two glass transition temperature of nylon-6 and polystyrene, respectively, it was confirmed that the compatibilizing blends of nylon-6 and polystyrene with the ionomer had their inherent phases. But the dispersed particle size of compatibilizing blends was significantly reduced compared to non-compatibilizing blends. This phenomena was more pronounced when ionomer of lower ionic content was added. Particularly the effect of interfacial adhesion was significantly enhance in case of using ionomer of lower ionic content. That is, when ionic content of ionomer was lower, ionomer was rich in polystyrene phase because of similar structure between polystyrene and ionomer, and ionomer specifically interacted with nylon-6. Therefore the concentration of ionomer in blends was high at the interface of nylon-6 and polystyrene. However, in case of higher ionic content of ionomer, this was different. As to reduced similarity effect, ionomer was rich in nylon-6 phase and the concnetration of ionomer in blends was low at the interface of nylon-6 and polystyrene. These morphological observations of blends easily made us foresee the variation of mechanical properties, except the blends of polystyrene matrix that the shrinkage of nylon-6 particle predominated. Really the better compatibilized blends using ionomer of lower ionic content showed high tensile strength compared to blends using ionomer of higher ionic content. From the results, it was possible to conclude that two factors influencing effects of particle size reduction and interfaical modification on morphology were characteristics of similar structure and specific interaction, and the compatibilizing effect was significantly enhanced when the ionic content of ionomer was low.
