Production and characterization of innovative carbon fiber polycarbonate composites

Vapor Grown Carbon Fiber (VGCF)-polycarbonate composites were produced using conventional processing and the performance of the parts thus produced was evaluated. The tensile properties of the composites were only marginally better than those of the nonreinforced polymer, and the impact resistance decreased with the incorporation of the fibers. In an attempt to understand this behavior, the rheological characteristics of the composites were studied, using rotational (steady and oscillatory) and capillary rheometry. A decrease in viscosity with fiber content was observed and explained in terms of poor fiber-matrix adhesion. Evidence of possible weak fiber structures forming above a critical concentration was also found.