聚丙烯/石墨导电纳米复合材料的制备与性能

用溶液插层及其与熔体混合相结合的母料熔体混合 (MMM)方法制备了聚丙烯 (PP) 马来酸酐接枝聚丙烯 (gPP) 膨胀石墨 (EG) (gPP EG =3 2wt)导电纳米复合材料 ,其室温逾渗阀值 (c)分别为 6wt%和 8wt % ,明显低于直接熔体混合制得复合材料和PP EG对照材料的c=11wt%和 12wt% .增加gPP含量 (Cg)能提高复合材料的电导率 (σ) ,例如对于MMM法制备的复合材料 ,固定PP gPP =1 1wt时 ,c 降为 7wt% ;保持EG含量 =9wt%时 ,σ在Cg>30wt %后跃升 7个数量级以上 .通过TEM、SEM和OM观察 ,从制备方法、EG和gPP含量影响复合材料形态和微结构的角度 ,分析说明了出现上述差异和现象的原因 .

PREPARATION AND PROPERTIES OF POLYPROPYLENE/GRAPHITE ELECTRICALLY CONDUCTIVE NANOCOMPOSITES

Polypropylene (PP)/maleic anhydride grafted polypropylene (gPP)/expanded graphite (EG) (gPP/EG = 3/2?wt) electrically conductive nanocomposites were prepared via solution intercalation (SI) and its combination with melt mixing named as masterbatch melt mixing (MMM).Room temperature electrical conductivity (σ) measurements revealed that the percolation thresholds ( c) of the nanocomposites prepared via SI and MMM were 6?wt% and 8?wt% respectively,much lower than those of the composite and the PP/EG control prepared via direct melt mixing( c = 11?wt% and 12?wt%).The increment of gPP content (C g) can elevate the σ of the composites,ex.when its composition became PP/gPP=1/1 wt,the  c of the composites prepared in MMM and DMM decreased to 7 wt% and 10 wt%,respectively;while for the nanocomposite prepared via MMM,in the case of fixing the EG content of 9 wt%,its σ might jump up more than 7 degress of magnitude as the C g exceeded 30 wt%.The reasons causing the above differences and phenomena mentioned above were analyzed and elucidated by means of TEM, SEM and OM observations and according to the differences among the preparation methods.