低密度隔热炭/炭复合材料高效制备及性能研究

Efficient Preparation and Properties of Low Density Heat-insulating Carbon/carbon Composites

以密度为0.18g/cm^(3)黏胶基炭毡为增强体,以糠酮树脂和硼酚醛树脂作为浸渍剂,通过低压真空浸渍工艺/常压炭化工艺制备了两种低密度隔热炭/炭复合材料。比较由糠酮树脂和硼酚醛树脂浸渍剂制备的低密度隔热炭/炭复合材料的压缩性能、导热系数、线膨胀系数并通过扫描电子显微镜(SEM)复合材料观察断口微观形貌。结果表明:由糠酮树脂浸渍剂制备的新型低密度隔热炭/炭复合材料的压缩强度较高,约5.54MPa。两种材料的应力-位移曲线和断口微观形貌阐释了材料压缩破坏方式为伪塑性断裂。由糠酮树脂和硼酚醛树脂浸渍剂制备的新型低密度隔热炭/炭复合材料1000℃下导热系数分别为约0.847W/(m·K)、0.918W/(m·K),25~1000℃的平均热膨胀系数分别为1.313×10^(-6)/℃、1.389×10^(-6)/℃。由此,由糠酮树脂浸渍剂制备的新型低密度隔热炭/炭复合材料具有较好的隔热性能和高温结构稳定性。

The low-density heat-insulating carbon/carbon composites were prepared by pressure impregnation/carbonization(PIC)method with 0.18g/cm^(3)viscose-based carbon felt as reinforcement and furfuryl ketone resin and boron phenolic resin as impregnation agent.The compressive properties,thermal conductivity and linear expansion coefficient of the low density heat-insulating carbon/carbon composites prepared by furfuryl ketone resin and boron-phenolic resin impregnation agent were compared.The fracture morphology of the composites was observed by scanning electron microscope(SEM).The results show that the compressive strength of the new low-density heat-insulating carbon/carbon composite prepared by furfuryl ketone resin impregnation agent is about 5.54MPa.The stress-displacement curves and fracture morphology of the two materials indicate that the compressive failure mode of the materials is pseudo-plastic fracture.The thermal conductivity of the new low-density heat-insulating carbon/carbon composites prepared by furfuryl ketone resin and boron-phenolic resin impregnation agent at 1000℃is about 0.847W/(m·K)and 0.918W/(m·K),respectively.The average thermal expansion coefficient of 25~1000℃is 1.313×10^(-6)/℃and 1.389×10^(-6)/℃respectively.Therefore,the new low density heat insulation carbon/carbon composite prepared by furfuryl ketone resin impregnation agent has better heat insulation performance and high temperature structure stability.