纺丝温度对新型高导热碳材料性能的影响

Effect of Spinning Temperature on Carbon Materials With High Thermal Conductivity

利用中间相沥青纤维的自粘结性和沥青大分子沿纤维轴高度择优取向的特点,通过热压方法制备高导热块体碳材料。在纺丝和氧化条件不变的情况下,主要考察了中间相沥青的熔融纺丝温度对纤维性能和目标材料性能的影响。结果显示:(1)熔融纺丝温度越高,中间相沥青纤维的直径越大;(2)在合适的纺丝温度下所得的纤维经氧化后热压制得材料具有较高的弯曲强度、密度、热导率以及较低的电阻率。选取纺丝温度为308℃,所纺中间相纤维直径为20μm,氧化后经热压所得材料的密度、弯曲强度、热导率和电阻率分别为2.02 g/cm3、128.7 MPa、597 W/(m.K)和1.25μΩ.m。

In this paper, block carbon materials with high thermal conductivity are formed directly from mesophase pitch fibers by means of hot-pressing methods. The technology uses the advantage of self-adhesion of mesophase pitch fibers and high preferred orientation created during melt spinning. When other spinning and oxidation conditions are not changed, the effect of spinning temperature of mesophase pitch on fibers diameter and properties of resulting materials is investigated. Results show ： （ 1 ） the higher spinning temperature is, the larger diameter of pitch fibers and higher content of oxygen element are; （2） resulting materials prepared from pitch fibers at appropriate spinning temperature, have high bending strength, high conductivity and density. In the experiment, pitch fibers with the diameter of 20 μm at spinning temperature of 308℃ are hot-pressed to form the carbon materials with thermal conductivity of 597 W/（m-K）, bending strength of 128.7 MPa, electrical resistivity of 1.25 μm and density of 2.02 g/cm^3.