中文摘要：

在低密度聚乙烯（LDPE）及其碳纳米管（CNTs）复合材料的热成型加工过程中施加稳恒强磁场，研究了磁场处理对LDPE及CNT/ LDPE复合材料直流电导特性的影响，并结合差示扫描量热、偏光显微镜与原子力显微镜分析探讨了磁场处理的作用机理。结果表明，磁场处理能导致LDPE的结晶度提高，体积电阻率增加；稳恒强磁场能在CNTs中“诱导”形成感应磁矩，使得CNTs沿平行于磁场方向在LDPE中取向，从而导致CNTs/LDPE复合材料沿平行于磁场方向的电导率增加，电导非线性特性提高；磁场处理导致CNT/ LDPE复合材料电导率增加的幅度随CNTs掺量的增加而增大。

英文摘要：

Low-density polyethylene （LDPE） and carbon nanotube （CNT） composites （CNT/LDPE） were treated during their hot-press molding using a strong static magnetic field. The effect of the magnetic field on the direct current electrical conductivity of these materials was investigated and the mechanism for the effect was analyzed by differential scanning calorimetry, polarized light microscopy and atomic force microscopy. Results indicate that the magnetic field treatment increases the degree of crystallization and the volume resistivity of the composites. The induced magnetic moment in the CNTs caused by the magnetic field leads to an improved orientation of the CNTs in LDPE along the magnetic field direction during molding, which causes an increase in the electrical conductivity of the CNT/LDPE composites in the magnetic field direction and an increase of nonlinear conductivity characteristics. The increased amplitude of electrical conductivity of the composites increases with the increasing amount of CNTs added.