Extrusion conditions and properties of vapor grown carbon fiber reinforced polypropylene

Vapor grown carbon fiber (VGCF) is a new and inexpensive carbon fiber produced by vapor deposition of hydrocarbons on metal catalysts. The ability to fabricate VGCF reinforced thermoplastic composites by extrusion provides the potential to exploit VGCF into new commercial markets. This study investigates the extrusion conditions and properties of VGCF reinforced polypropylene. Extrusion was carried out using a Leistritz; twin-screw extruder. Polypropylene reinforced with 0% to 12.5% volume fraction VGCF was extruded successfully at temperatures ranging from 215 degreesC to 250 degreesC. The extrusion pressure increased and the flow rate decreased as the percentage of fiber was increased. Increases in tensile strength and modulus were observed by the addition of VGCF. However, the void content of the composite samples increased with fiber content.