Strain-dependent electrical resistance of epoxy/MWCNT composite after hydrothermal aging
Strain-dependent electrical resistance of epoxy/MWCNT composite after hydrothermal aging
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DOI：
10.1016/j.compscitech.2015.06.004
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发表时间：
2015-09-29
影响因子：
9.1
通讯作者：
Aniskevich, A.
中科院分区：
文献类型：
--
作者：
Starkova, O.;Mannov, E.;Aniskevich, A.
研究了环氧/多壁碳纳米管（MWCNT）复合材料在湿气和水热老化作用下的电阻。对具有不同史前环境暴露史的样品进行了拉伸测试，并测量了测试过程中电阻的响应。测试样品的电阻变化与应变的总体模式由线性和非线性区域组成，其宽峰先于样品的极限强度，并发生在应力应变曲线中明显塑性变形的开始处。 1VIWCNT5含量较低的复合材料表现出更明显的非线性行为，电阻随应变的增加率明显更高，这归因于隧道型电阻的主导作用。样品的水分和吸水导致其电阻增加。这一事实的解释是，由于环氧树脂膨胀和水热引起的多壁碳纳米管导电网络的结构变化，隧道电阻增加。在不同湿气和水热条件下处理的样品显示出不同的应变依赖性电阻响应，这与水分/水吸收水平没有直接关系。在低应变值下，环氧树脂/MWCNT复合材料的应变传感功能仅受老化条件的轻微影响。 (C) 2015 Elsevier Ltd. 保留所有权利。
The electrical resistance of epoxy/multi-wall carbon nanotube (MWCNT) composites was studied under the effect of hygro- and hydrothermal aging. Tensile tests were conducted and the responses in the electrical resistance were measured during the tests for samples with different prehistory of environmental exposure. The overall pattern of the electrical resistance change versus strain for the samples tested consists of linear and nonlinear regions with a broad peak that precedes the ultimate strength of the sample and occurs at the onset of evident plastic deformation in the stress strain curve. The composite with lower content of 1VIWCNT5 exhibits a more pronounced nonlinear behavior and the rate of resistance increase with strain is significantly higher that is attributed to a dominant role of the tunneling-type resistance. Moisture and water uptake of the samples resulted to an increase of their electrical resistance. This fact is explained by the increased tunneling resistance due to epoxy swelling and hydrothermally-induced structural variations of the MWCNT conductive network. Samples conditioned under different hygro- and hydrothermal conditions show different strain-dependent response of the electrical resistance, which is not directly related to the level of moisture/water uptake. Under low strain values, strain sensing functionality of epoxy/MWCNT composites is only slightly affected by aging conditions. (C) 2015 Elsevier Ltd. All rights reserved.