Miscibility behaviour of poly(ether sulphone)/Nylon-6 blends

Binary blends of poly(ether sulphone) (PES) and Nylon-6 were prepared in a whole range of composition by melt extrusion. Miscibility behaviour of the blends were studied using thermal analytical techniques like differential s canning calorimetry (DSC) and dynamic mechanical analysis (DMA). Due to the rapid crystallization of Nylon-6 as it is cooled from the melt state, its glass transition behaviour could not be detected even in the quenched sampl es by DSC. Furthermore, the crystallization and melting behaviour of the bl ends have been studied by DSC. DMA results show that the dynamic storage mo dulus of the blends were in-between those of the constituent polymers. Also the glass transition of Nylon-6 phase as determined by the peak in loss ta ngent remains constant which shows that the two polymers are immiscible. Th ermal expansion coefficient of the blends as determined by TMA is greater t han that of Nylon-6 signifying the increased dimensional stability of the b lends at higher temperatures. Morphological studies done by scanning electr on microscopy (SEM) show the biphasic nature of the blends, with clear cut boundaries between the phases because of poor interfacial adhesion. Dispers ed particle size is small when Nylon-6 is the dispersed phase because of it s lower melt viscosity as compared to PES. Thermal stability of the blends was measured using thermogravimetric analysis (TG). Two-step decomposition behaviour was observed because of macro-phase separated morphology.