Preparation and characterization of large diameter pitch based carbon fiber/ABS resin composites with high thermal conductivities

Parallel, stretched and evenly arranged mesophase pitch based graphitized carbon fibers with diameters of 50-53 μm were coated with different amounts of acrylonitrile butadiene styrene (ABS) resin, and hot-pressed to produce carbon fiber/ABS resin composites. The morphology, optical texture and crystal structure of the carbon fibers and their composites were characterized by scanning electron microscopy, polarized light microscopy and X-ray diffraction. The influence of the graphitization temperature and fiber content on the thermal conductivity of the composites was investigated. The thermal diffusivity and thermal conductivity of the composites along both fiber axial and radial directions showed an obvious difference, owing to the high orientation of the graphite crystals along the axial direction of the carbon fibers. The thermal diffusivity of the composites along the carbon fiber axial direction increased both with the graphitization temperature and fiber content. The composite with 54 vol.% carbon fibers graphitized at 2 900 ℃ showed the highest thermal conductivity.