Miscibility behaviour of poly(ether ether ketone)/poly(ether ketone) blends – thermal and morphological studies

In the present investigation the blends comprising of poly(ether ether ketone) and poly(ether ketone) have been prepared by melt extrusion. Miscibility behaviour of the blends was studied by differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). A single glass transition temperature (Tg) varying linearly with composition was obtained. Also a single melting endotherm was observed for all compositions, which shows that the blends are isomorphic in nature. Crystalline melting point (Tm) of the blends is essentially same as those of higher melting constituent until high levels of low melting constituent are present. SEM results show that there is homogeneous dispersion of the blend components and a single phase behaviour was observed. Flexural strength and modulus shows almost additive behaviour except at some compositions where synergistic behaviour was seen.