EFFECT OF MELT ANNEALING ON THE MORPHOLOGY AND PROPERTIES OF POLYCARBONATE BLENDS

The effect of quiescent annealing for brief periods at melt-processing temperatures (e.g., 270-degrees-C) were designed to simulate certain conditions that can occur during molding or extrusion. It was found that significant changes in the phase morphology of polycarbonate-based blends can occur in less than 2 min under these conditions. Such morphological rearrangements are detrimental to the mechanical properties of multiphase blends of polycarbonate with rigid polymers, viz., polystyrene, poly (methyl methacrylate), and styrene/acrylonitrile copolymers and core-shell impact modifiers.