MISCIBILITY AND SYNERGISTIC EFFECT OF IMPACT STRENGTH IN POLYCARBONATE ABS BLENDS

Miscibility and mechanical properties of polycarbonate/acrylonitrile-butadiene-styrene (PC/ABS) blends prepared by a continuous kneader-type extruder were investigated. It was found that the PC/ABS blend consists of the miscible PC/SAN phases and immiscible PC/PB phases, which agrees well with that predicted by the group contribution method of solubility parameters. Differences in calculated solubility parameter (DELTA-delta) are 0.20 (cal cm-3)1/2 for the PC/SAN pair and 1.85 (cal cm-3)1/2 for the PC/PB pair. Interestingly, the impact strength of the present PC/ABS blends exhibits a synergistic effect over a much wider range of polycarbonate content, i.e. 20%-80%, than that of the previously reported ones. This may be attributed to the enhanced mixing and low butadiene content. However, further work on the relationship with the rubber particle size is required to understand fully this observation.