【摘要】 文摘采用热塑性酚醛树脂为原料,通过液相低压发泡工艺制备得到具有纳米孔径的酚醛树脂基泡沫碳前驱体。研究了前驱体的隔热机理和纳米孔径结构对热导率的改善以及材料的热导率随体积密度和测试温度的变化规律。结果表明,由于具有均匀分布的纳米孔径结构,前驱体的隔热性得到改善和提高。前驱体的热导率随体积密度的增大存在一个最佳密度点,此时热导率取得极小值。200℃以前,前驱体的热导率随测试温度的升高先增后减,200℃以后热导率变化甚少,高密度的前驱体出现极大值拐点的温度比低密度前驱体延缓20℃。更多还原

【Abstract】 Phenolic-based carbon foam precursor with nanometer pore structure was prepared with thermoplastic phenolic resin through liquid phase foaming technology under low-pressure.The insulation mechanism,the improvement of nanometer pore structure on the insulation properties and the change laws of the effective thermal conductivity of the precursor material with the bulk density and temperature were studied.The results show that the insulation properties of phenolic-based carbon foam precursor are improved by nanometer pore structure.As bulk density increasing,there is an optimium density value in which the effective thermal conductivity of the carbon foam precursor has the lowest value.The effective thermal conductivity of the carbon foam precursor first increased and then decreased as temperature increasing before 200℃.The turning temperature of the thermal conductivity of the carbon foam precursor with bigger volume density is higher than that with lower volume density.更多还原