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在挤出过程加入超声振动作用,研究超声振动对高石墨烯微片(GNP)含量的聚丙烯基(GNP/PP)复合材料微观形态、结晶、导电性和导热性的影响。结果表明:由于超声振动提供强烈的冲击波与微射流,挤出过程中加入超声振动可有效地减薄GNP片层厚度,减少GNP团聚,增强GNP在PP中的分散均匀性,有利于构建导电导热网络,从而提高GNP/PP纳米复合材料的导电导热性能。相较于无超声振动,加入100 W超声振动后,GNP含量越高,GNP/PP电导率和热导率提升幅度越大,在GNP含量为15wt%时,电导率升幅为85%,热导率升幅为9.7%。而在GNP含量同为12wt%时,随着超声振动功率的增加,电导率和热导率呈现先增大后减少的规律。当超声功率为200 W时,电导率升幅为214%,热导率升幅为17.2%。而超声功率达到300 W时,较高功率的超声振动使部分石墨烯微片的片径减少,导致片层间更难以搭建完整的导电导热网络,使GNP/PP性能均略有下降。
The effects of ultrasonic vibration on the morphology, crystallinity, electrical conductivity and thermal conductivity of GNP / GNP composites were studied by adding ultrasonic vibration during the extrusion process. The results show that ultrasonic vibration can provide intense shock wave and micro-jet flow, and ultrasonic vibration during extrusion can effectively reduce the thickness of GNP, reduce the agglomeration of GNP and enhance the dispersion of GNP in PP, which is conducive to the construction of conductive heat conduction Network, thereby improving the conductive and thermal conductivity of GNP / PP nanocomposites. Compared with no ultrasonic vibration, the higher the GNP content is, the greater the increase of GNP / PP conductivity and thermal conductivity is. When the GNP content is 15wt%, the conductivity increases by 85% The rate of increase was 9.7%. However, with the same GNP content of 12wt%, the conductivity and thermal conductivity increase first and then decrease with the increase of ultrasonic vibration power. When the ultrasonic power is 200 W, the conductivity increases by 214% and the thermal conductivity increases by 17.2%. When the ultrasonic power reaches 300 W, the higher power ultrasonic vibration reduces the diameter of some graphene sheets, which makes it more difficult to build a complete conductive heat conduction network between the layers, resulting in a slight decrease of GNP / PP performance.