Miscibility level and properties of poly(ether imide)/poly(ethylene terephthalate) blends

Blends composed of poly(ether imide) and poly(ethylene terephthalate) were obtained both by kneading followed by compression molding and by direct injection molding. Both procedures gave rise, probably at all compositions, to biphasic structures with similar homogeneity that showed wide single T g peaks by dynamic-mechanical analysis. The modulus of elasticity and the yield stress values appeared, respectively, close to and above those predicted by the additivity rule, probably due to the density increase and slight orientation observed. The ductility values against composition appeared well below the additive values, probahly due to the presence of a dispersed phase together with the notch-sensitive nature of the blends.