Structure and properties of electrically conducting composites consisting of alternating layers of pure polypropylene and polypropylene with a carbon black filler
Structure and properties of electrically conducting composites consisting of alternating layers of pure polypropylene and polypropylene with a carbon black filler
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由纯聚丙烯和带有炭黑填料的聚丙烯交替层组成的导电复合材料的结构和性能
DOI：
10.1016/j.polymer.2008.08.056
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发表时间：
2008-10-17
期刊：
影响因子：
4.6
通讯作者：
Jiang, Songling
中科院分区：
文献类型：
--
作者：
Xu, Shuangxi;Wen, Ming;Jiang, Songling
采用多层共挤出法制备了聚丙烯（PP）和炭黑（CB）交替填充聚丙烯（PPCB）层的导电复合材料。通过改变倍增单元的数目，可以控制CB在PPCB层中的选择性位置，形成共连续结构，并由于双逾渗效应降低了多层复合材料的逾渗阈值和电阻率。这种双重渗滤可以在使用多层共挤出的单一聚合物基质中实现，而它只能通过常规方法在两种不同的聚合物基质中生产。结果表明，多层共挤出过程中，水平扩散流和垂直复合所产生的剪切力对CB聚集体在PPCB层中的分散有很大影响。多层复合材料的电阻率、正温度系数效应和力学性能与其层数密切相关。与常规复合材料相比，PPCB层发生了脆韧转变。有趣的正负温度系数效应发生在结晶过程中，并依赖于层数。提出了一种机制来解释这些现象。(C)2008爱思唯尔有限公司保留所有权利。
Electrically conducting composites consisting of alternating polypropylene (PP) and carbon black (CB)filled polypropylene (PPCB) layers were prepared by multilayered coextrusion. The co-continuous structure with selective location of CB in PPCB layers was controllable by changing the number of multiplying elements, and decreased the percolation threshold and electrical resistivity of multilayered composites because of the double percolation effect. This double percolation could be achieved in a single polymer matrix using multilayered coextrusion, whereas it can only be produced in two different polymeric matrices by conventional approaches. Results showed that the dispersion of CB aggregates in PPCB layers was greatly affected by the shearing forces induced by the horizontal spreading flow and vertical recombination occurring during the multilayered coextrusion. The electrical resistivity, positive temperature coefficient effect and mechanical properties of multilayered composites depended strongly on their number of layers. A brittle-ductile transition occurred in PPCB layer compared with the conventional composites. The interesting positive and negative temperature coefficient effects occurred during crystallization and depended on the number of layers. A mechanism is proposed to explain these phenomena. (C) 2008 Elsevier Ltd. All rights reserved.