多级拉伸PP/PA1010/CB导电复合材料的结构与性能

Structure and Properties of Polypropylene/Polyamide1010/Carbon Black Composites Prepared Through Multistage Stretching Extrusion

利用自主设计的多级拉伸挤出设备,制备了含不同长径比的聚酰胺/炭黑(PA1010/CB)纤维的原位微纤聚丙烯/聚酰胺/炭黑(PP/PA1010/CB)导电复合材料,炭黑仅选择性分散在PA1010中,形成一种特殊的双逾渗现象。扫描电子显微镜观察、电学性能测试结果表明,随着分割叠加单元个数的增加,(PA1010+CB)导电相经历了由球状变成高长径比纤维状,然后纤维被拉断成短纤维,最后又重新拉伸成长纤维的过程。相应地,其体积电阻率也随着导电相形态的演变而先急剧下降,然后上升,最后又降低,电阻率最大下降了5个数量级。复合材料的形态演变和导电性能都极大地依赖于分割叠加单元(LME)个数。

The polypropylene/polyamide 1010/carbon black（PP/PA1010/CB） composites with in situ microfibrillar morphology were prepared through multistage stretching extrusion.CB was selectively located in PA1010.With the increase in the number of laminating-multiplying element（LMEs） from zero to seven,the conductive PA1010/CB phase was found to experience an elongating-breaking-reelongating process along the flow direction in the PP matrix.This morphological development,induced by a strong shearing or stretching force,resulted in the strong dependence of electrical resistivity on the LME number.When no LME was used,PP/PA1010/CB materials with 2% CB employed were insulators with very high electrical resistivity due to their droplet morphology.With the introduction of LMEs,a conductive network was easily formed due to the microfibrillation of the conductive PA1010/CB phase.These materials became conductors with low electrical resistivity.The largest decrease of electrical resistivity was higher than five orders of magnitude.