Oscillations of the electrical resistance induced by shear deformation in molten carbon black composites
Oscillations of the electrical resistance induced by shear deformation in molten carbon black composites
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DOI：
10.1016/j.polymer.2012.12.051
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发表时间：
2013-02
期刊：
影响因子：
4.6
通讯作者：
J. Krückel;Z. Starý;D. Schubert
中科院分区：
文献类型：
--
作者：
J. Krückel;Z. Starý;D. Schubert
在熔融状态下，对含炭黑的聚甲基丙烯酸甲酯在振荡剪切作用下的时变电阻进行了监测。测得的电信号精确地以振荡剪切变形的两倍频率振荡。此外，实验结果为剪切变形下聚合物熔体导电结构的发展提供了线索。结果表明，在剪切变形开始时，流动诱导的导电路径破坏比流动诱导的建立更占优势。然而，在较长的时间内，竞争效应达到动态平衡，只有热诱导的路径建立影响剪切过程中复合材料阻力的变化。此外，振荡电响应明显取决于施加的变形幅度。此外，推导了一个描述剪切变形下导电通道行为的简单物理模型，并用于描述实验数据。
The time-dependent electrical resistance of polymethylmethacrylate containing carbon black was monitored under oscillatory shear in the molten state. The electrical signal measured was oscillating exactly at the doubled frequency of the oscillatory shear deformation. Moreover, the experimental results gave a hint to the development of conductive structures in polymer melts under shear deformation. It was shown that the flow induced destruction of conductive paths dominates over the flow induced build-up in the beginning of the shear deformations. However, for longer times both competitive effects reach a dynamic equilibrium and only the thermally induced build-up of pathways influences the changes in the composite resistance during the shear. Moreover, the oscillating electrical response depends clearly on the deformation amplitude applied. Furthermore, a simple physical model describing the behaviour of conductive pathways under shear deformation was derived and utilized for the description of the experimental data.