【摘要】 用溶液插层(SI)和母料熔体混合(MMM)方法制备了聚乙烯(PE)/马来酸酐接枝聚乙烯(gPE)/膨胀石墨(EG)导电纳米复合材料,以直接熔体混合(DMM)法制备的PE/gPE/EG、PE/EG复合材料作对照,通过电导率(σ)测试,TEM、SEM、OM观察和DSC分析,研究了制备方法、EG体积或质量分数(或fm)和gPE质量含量(Cg)对复合材料结构和σ的影响。结果表明,SI、MMM、DMM法制备的Cg/fm=1 5复合材料和PE/EG对照材料的逾渗阈值c分别为2 19%、3 81%、4 68%和5 35%;当Cg/fm由1增至4时,MMM、DMM法制备的fm=9%复合材料的σ分别跃升12和8个数量级;产生这些差异和现象的原因,可根据复合材料中EG分散相形态和内部微结构随制备方法、和Cg/fm的变化,按逾渗理论来解释。更多还原

【Abstract】 Polyethylene (PE)/maleic anhydride grafted polyethylene (gPE)/ expanded graphite (EG) electrically conductive nanocomposites were prepared by solution intercalation (SI) and masterbatch melt mixing (MMM) methods. The electrical conductivity (σ) measurement, TEM, SEM and OM observations as well as DSC analysis were used to examine the influences of preparation methods, EG volume or mass fractions ( or f_m) and gPE mass contents (C_g) on structure and σ of the nanocomposites, as compared with PE/gPE/EG composites and PE/EG control materials prepared by direct melt mixing (DMM) method. The percolation thresholds (_c) of the SI-, MMM-, DMM-composites with C_g/f_m=1.5 and the DMM-PE/EG controls were determined to be 2.19%, 3.81%, 4.68% and 5.35%, respectively. As the C_g/f_m increased from 1 to 4, the σ of the MMM-, DMM-composites with f_m=9% rose by 12 and 8 orders of magnitude, respectively. These were closely associated with the morphology and internal microstructure of EG dispersed phase in the composites varying with preparation methods,  and C_g/f_m, and could be interpreted in terms of percolation theory.更多还原