Rheological and Mechanical Properties of Polypropylene Filled with Vapor-Grown Carbon Fiber

Rheological and mechanical properties of polypropylene filled with dilute Vapor-Grown Carbon Fibers (VGCF) were examined. VGCF were premixed with polypropylene by a mix and beat machine and the mixture was subsequently compounded by a screw extruder. The viscosity of the composites containing less than 7.5% VGCF concentration, measured by capillary rheometry, decreases compared with that of the raw resin in wide ranges of both shear rate and resin temperature. The tensile strength of the 0.1% VGCF composites increases 8.5% and the Young's modulus increases 11.4% while keeping the essential elongation property of polypropylene.