227 Injection Molding of Polystyrene Matrix Composites Filled with Vapor Grown Carbon Fiber

Abstract

Vapor grown carbon fiber (VGCF) is a kind of carbon nanotube (CNT), which has outstanding properties such as high mechanical strength and electrical conductivity. We studied injection molding of VGCF reinforced polystyrene (PS) and evaluation of the mechanical and electrical properties comparing with the composites in which conventional carbon fillers were filled. As a result, the resistivity of the composites reinforced with VGCF drops significantly between 3 and 4 vol.% and after which it decreases linearly above 4 vol.%. The resistivity of the composites reinforced with VGCF is 1.2×(10)^2Ω・cm when the VGCF concentration is 11.6 vol.%. The resistivity is significantly lower than that of the composites which were reinforced with conventional carbon fillers. The elastic modulus slightly improves with increasing VGCF concentration, whereas the tensile strength is almost constant in the VGCF concentration range from 0 to 12 vol.%.