论文部分内容阅读
为了提高聚丙烯(PP)的导热性能,扩大其使用范围,采用价格低廉的商用石墨对PP进行改性,利用转矩流变仪制备了PP/石墨导热复合材料。研究了粒径为2μm和20μm的石墨及其复配对复合材料热导率及力学性能的影响。结果表明,复合材料的热导率随着石墨用量的增加而显著增大,20μm石墨填充的复合材料热导率高于2μm石墨填充的复合材料;由于石墨的各向异性,层内热导率远高于层间热导率;将两种粒径的石墨复配,固定石墨总质量分数为40%,当2μm石墨与20μm石墨质量比为1︰5时,复合材料层间和层内热导率达到最大,分别为1.125 W/(m·K)和2.897 W/(m·K),比相同用量下单一2μm石墨填充PP分别提高了121%和61%,比单一20μm石墨填充PP分别提高了3.6%和20%。随石墨用量增加,单一粒径石墨填充的复合材料拉伸强度和弯曲强度呈现先减小后增大的趋势,随复配填料中20μm石墨用量增加,复配填料填充复合材料的力学性能呈下降趋势,但弯曲强度变化不大,拉伸强度也在10 MPa以上。
In order to improve the thermal conductivity of polypropylene (PP) and expand the scope of its application, PP was modified with low-cost commercial graphite. PP / graphite thermal-conductive composites were prepared by torque rheometer. The effects of graphite with sizes of 2μm and 20μm on the thermal conductivity and mechanical properties of the composites were studied. The results show that the thermal conductivity of composites increases significantly with the increase of graphite content. The thermal conductivity of 20μm graphite filled composites is higher than that of 2μm graphite-filled composites. Because of the anisotropy of graphite, the thermal conductivity of layers is far Higher than the thermal conductivity of the interlayer; the two particle size of graphite compounded, the total mass fraction of fixed graphite is 40%, when the mass ratio of 2μm graphite and 20μm graphite is 1: 5, the intermetallic and interlaminar thermal conductivity (1.125 W / (m · K) and 2.897 W / (m · K) respectively), which increased by 121% and 61% respectively compared with single 2μm graphite-filled PP at the same dosage, which was higher than that of single 20μm graphite-filled PP 3.6% and 20%. With the increase of graphite content, the tensile strength and flexural strength of single-particle graphite filled composites decrease first and then increase. With the increase of the amount of graphite 20μm, the mechanical properties of composite filled with filler decreased Trend, but little change in bending strength, tensile strength is also above 10 MPa.