聚丙烯/碳纳米管复合材料的结晶和介电行为

Crystallization and Dielectric Behavior of Polypropylene/Carbon Nanotubes Composites

采用熔融共混制备了聚丙烯/碳纳米管复合材料(PP/MWCNTs)。利用场发射扫描电镜(FESEM)、差示扫描量热仪(DSC)、偏光显微镜(POM)、X射线衍射仪(XRD)及宽频介电仪(BDS)对复合体系的形态、非等温结晶行为、结晶结构以及介电行为进行了研究。结果表明,碳纳米管均匀分散于聚丙烯基体中,二者界面结合紧密;极少量碳纳米管的加入即对聚丙烯的结晶起显著的异相成核作用,促进聚丙烯α晶型的形成;此外,复合体系在导电逾渗阀值附近介电松弛行为显著加强。

Polypropylene/muhi-walled carbon nanotube composites （PP/MWCNTs） were prepared directly by melt mixing. The morphology, crystallization and dielectric behavior of the composites were investigated by the field emission scanning electron microscope （FESEM）, differential scanning calorimeter （DSC）, polarized optical microscope （POM）, X-ray diffractometer （XRD） and broadband dielectric spectrometer （BDS）, respectively. The results show that MWCNTs present nice dispersion in the PP matrix. Very small addition of MWCNTs has remarkable nucleation effects on the crystallization of PP, which promotes the formation of α crystal. Moreover, the composites show a strong dielectric relaxation behavior at the MWCNTs loading levels of around the conductive percolation threshold.