用溶液共混的方法将碳纳米管（CNTs）分散在聚乳酸聚已酸内酯（PLLA-PCL）嵌段共聚物中，再采用熔融共混的方法，制备了CNTs/PLLA-PCL/PS复合材料。扫描电镜和高分辨率光学显微镜观察发现，CNTs能够较均匀地分散在PLLA-PCL。电导率的测定表明，CNTs的加入大幅度提高了聚苯乙烯的导电性能，与CNTs//PS复合材料相比，PLLA-PCL的加入对更加有效地分散CNTs。

以聚丙烯和低密度聚乙烯共混物为基体，用碳黑为填充材料制备了复合导电材料，导电性能的测试表明多相复合体系的渗滤阈值低于两相复合体系的渗滤阈值。对复合材料PTC效应的分析以及时材料的热性能测试结果表明碳黑在共混体系中的分布。同时探讨了体乐碳黑含量的变化对PTC效应的影响。

A new method was developed to disperse carbon nanotubes (CNTs) in a matrix polymer and then to prepare composites by melt processing technique. Due to high surface energy and strong adsorptive states of nano-materials, single-walled carbon nanotubes (SWNTs) were adsorbed onto the surface of polymer powders by spraying SWNT aqueous suspected solution onto fine high density polyethylene (HDPE) powders. The dried SWNTs/powders were blended in a twin-screw mixture, and the resulting composites exhibited a uniformly dispersion of SWNTs in the matrix polymer. The electrical conductivity and the rheological behavior of these composites were investigated. At low frequencies, complex viscosities become almost independent of the frequency as nanotubes loading being more than 1.5 wt%, suggesting an onset of solid-like behavior and hence a rheological percolation threshold at the loading level. However, the electrical percolation threshold is 4 wt% of nanotube loading. This difference in the percolation thresholds is understood in terms of the smaller nanotube-nanotube distance required for electrical conductivity as compared to that required to impede polymer mobility. The measurements of mechanical properties indicate that this processing method can obviously improve the tensile strength and the modulus of the composites.