Processing and composition dependence of the structure and mechanical properties of polycarbonate/ultrax blends

Polycarbonate (PC)/Ultrax blends were obtained by injection molding changing both the Ultrax content and the injection temperature, speed and pressure. The change of injection speed or pressure did not lead to significant change of morphology or properties. An injection temperature of 300°C allowed some reaction to take place between the components and the presence of some reacted Ultrax in the PC‐rich phase, but the mainly spherical morphology obtained lead to poor mechanical properties. At a lower injection temperature of 280°C, however, reactions were almost not detected, but fibrillar structures were produced, mainly because of the higher matrix viscosity. This gave rise to important increases not only in modulus and tensile strength but also in flexure properties and creep dimensional stability.