【摘要】 用熔融共混法制备了聚丙烯多壁碳纳米管(PP MWNTs)复合材料,TGA研究表明在氮气气氛下碳纳米管显著增加了聚丙烯基体的热稳定性.3wt%MWNTs可使PP热分解起始温度提高44℃.非等温结晶研究表明MWNTs对PP基体的结晶行为没有明显的影响.流变测试结果表明PP MWNTs复合材料的储能模量G′和损耗模量G″随着MWNTs含量增加逐渐增大.1wt%MWNTs的PP聚合物的零剪切粘度最低,5wt%MWNTs的PP聚合物的零剪切粘度最高,PP和3wt%MWNTs的PP纳米聚合物的零剪切粘度居于二者之间,随着频率的增加,剪切稀化作用越来越明显,呈现出假塑性流体行为.含5wt%MWNTs的PP复合材料的体积和表面电阻率与纯PP相比分别下降了9个和4个数量级,表明少量的MWNTs可以显著改变PP的电学性能.更多还原

【Abstract】 Nanocomposites based on polypropylene (PP) and multi-walled carbon nanotube (MWNTs) were manufactured by melt blending.Thermal gravimetric analysis (TGA) showed that carbon nanotubes significantly enhanced the thermal stability of polypropylene in nitrogen.The temperature of onset decomposition was 44 K higher than that of neat PP for nanocomposites with 3 wt% of MWNTs loaded.The effect of MWNTs on the crystallization and melting behavior of polypropylene was not observed.Rheological behavior of PP/MWNTs nanocomposites showed that storage modulus (G′) and loss modulus (G″) increased with increasing nanotube content.At low frequency,the steady shear viscosity of nanocomposites with 1 wt% of MWNTs was minimal and that of the sample with 5 wt% nanotube was maximal.Shear thinning tendency increased with increasing frequency .The volume resistivity and surface resistivity of nanocomposite with 5 wt% MWNTs were 9 and 4 order of magnitude,respectively lower than those of the neat PP.It shows that the electrical conductivity can be improved obviously by incorporating a little MWNTs.更多还原