The Preparation And Investigation Of ABS Resin Composites Reinforced By Pitch Based Carbon Fibers

In this thesis,round-shaped pitch fibers with micrometer-scale were prepared by ameit-spinning method using a naphthalene-based mesophase pitch as a raw material, and highlyoriented round-shaped graphite fibers with high thermal conductivity were obtained throughpre-oxidation, carbonization and graphitization.，and its use as reinforcement and thermallyconductive medium, the acrylonitrile butadiene styrene (ABS) resin is used as the base material.Parallel stretched and evenly arranged mesophase pitch based graphitized carbon fibers werecoated with different contents of ABS resin, and then were hot-pressed to produce carbonfiber/ABS resin composites. The morphologies, optical texture and crystal structure of carbonfibers and their composites with ABS resin were characterized by scanning electron microscopyand polarized light microscopy and X-ray diffraction analyses. The influence of the content offibers、the diagram of fibers、the graphitization temperature and the arrangement of fibers onthe thermal conductivity and stock resistance of composites was also investigated. The mainconclusions of the work were obtained as follows:1. The thermal conductivity of composites along carbon fiber axial direction increaseswith the content of fibers、 diagram of fibers and graphitization temperature. Thegraphitization temperature had a greater influence on the thermal conductivity of the1D and2D composites made with larger fiber diameter. The1D and2D composite prepared from38vol.%fibers graphitized at2900℃and diagram with50~53μm possesses a high thermalconductivity of469.79W/m K and490.07W/m·K at room temperature, respectively.2. XRD and PLM analyses show that the1D and2D composites prepared exhibits astructural anisotropy. Round-shaped fibers have been unidirectionally distributed in thecomposite block. The internal graphitic layers possess a higher digree of orientation parallel tothe longitudinal direction of the Round-shaped. The1D and2D composite block shows obviousthermal anisotropy and has excellent thermal conductivities along the longitudinal direction ofthe Round-shaped. The room-temperature thermal conductivities of the composite are vary asmuch as80times of along the longitudinal direction and along the radial fiber direction.3. SEM analyses show that round-shaped fiber and ABS rein matrix compact connection inthe1D and2D composites prepared. The two phase interface combination is good and no evidentcracks and holes.4. The thermal conductivity of the2D composite are higher than1D composite preparedfrom fibers graphitized at2900℃and diagram with50~53μm, but when the diagram of fibersare at11~14μm、18~21μm and29~32μm, the thermal conductivity of the2D composite arehigher than1D composite prepared from26vol.%、24.8vol.%and24.5vol.%fibers graphitizedat2900℃, respectively.5. The stock resistance of composites along carbon fiber axial direction increases with thecontent of fibers and the2D composite are higher than1D composite prepared from fibersgraphitized at2700℃and diagram with50~53μm.The1D and2D composite prepared from 38vol.%fibers graphitized at2700℃and diagram with50~53μm possesses a high stockresistance of21KJ/m~2�'�19KJ/m~2, respectively.