Preparation and Structure Characterization of Mesophase Pitch-based Carbon Foam

Green foams were prepared from a petroleum-derived mesophase pitch by using the size-restriction foaming method and the foams were further oxidized, carbonized and graphitized, consequently carbon foams with excellent cell structure were obtained. SEM and XRD were used to observe the morphologies and analyze the structures of foams. The results show that the cell size can be altered by controlling the free space in mold. During carbonization and consequently graphitization of foams, cell diameter reduces and the orientation of molecules in cell walls improves, approaching that of graphite. The walls of foam cells are built up by even ones and Y type junctions. The former has better molecular orientation than the latter. It is also found that the foam with large cells will have more close-grained molecular arrangement, but the crystallites in them are smaller.