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以中间相沥青和添加中间相炭微球的沥青为原料,调整发泡压力和发泡温度制备沥青泡沫,经1273K炭化和2973K石墨化,制备了高密度石墨泡沫。为了进一步提高石墨泡沫的密度,采用573 K的沥青反复浸渍炭化未添加中间相炭微球的沥青在1273K下所制的泡沫炭,再经2973K石墨化获得增密度后的石墨泡沫。而后制备了相应石墨泡沫/石蜡复合材料。研究了石墨泡沫热物理性能的影响因素和石墨泡沫/石蜡复合材料的热行为。研究表明:沥青组分、发泡温度和发泡压力决定了石墨泡沫的结构和热物理性能,而石墨泡沫的热导率决定了复合材料的热行为。与石蜡相比,石墨泡沫/石蜡复合材料的热扩散系数提高了768至1588倍。石墨泡沫/石蜡复合材料的潜热与石蜡的质量分数成正比。该复合材料是快速响应电子散热材料的良好选择。
The pitch foam with mesophase pitch and mesocarbon microbeads was prepared as raw material, and the foaming pressure and foaming temperature were adjusted to prepare asphalt foam. After 1273K carbonization and 2973K graphitization, high density graphite foam was prepared. In order to further improve the density of graphite foam, 573 K of pitch was used to impregnate carbonized carbon foam with no added mesocarbon microbeads at 1273 K for 12 hours, and then graphitized at 2973K to obtain densified graphite foam. Then the corresponding graphite foam / paraffin composites were prepared. The influencing factors of thermal physical properties of graphite foam and the thermal behavior of graphite foam / paraffin composites were studied. The results show that the bitumen composition, foaming temperature and foaming pressure determine the structure and thermophysical properties of graphite foam, while the thermal conductivity of graphite foam determines the thermal behavior of the composites. Compared with paraffin, graphite foam / paraffin composite thermal diffusivity increased by 768 to 1588 times. The latent heat of graphite foam / paraffin composites is proportional to the mass fraction of paraffin wax. The composite is a good choice for fast response to electronic thermal materials.