Dielectric properties of modified graphene oxide filled polyurethane nanocomposites and its correlation with rheology
Dielectric properties of modified graphene oxide filled polyurethane nanocomposites and its correlation with rheology
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DOI：
10.1016/j.compscitech.2014.08.025
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发表时间：
2014-11-19
影响因子：
9.1
通讯作者：
Grohens, Yves
中科院分区：
文献类型：
--
作者：
Sadasivuni, Kishor Kumar;Ponnamma, Deepalekshmi;Grohens, Yves
本研究旨在研究含有亲水性氧化石墨烯（GO）和/或疏水性改性氧化石墨烯（mGO）片的增强聚氨酯（PU）纳米复合材料的动态力学、介电和流变性能。用4，4 '-亚甲基双（苯基异氰酸酯）（MDI）对GO进行有机改性，并通过溶剂混合法制备样品。我们发现，与添加GO相比，添加mGO提供了介电常数的更显著的增加。扫描电子显微镜（SEM）和X射线衍射（XRD）光谱证明了与未改性的GO相比，mGO的薄剥离片在PU基质中的更有效的分散。这种定性形态观察与从动态力学分析、流变学和介电研究中推断的定量结果相关。注意到所有纳米复合材料的粘弹性Payne效应和填料-填料和聚合物-填料的相互作用进行了研究，通过应用克劳斯和迈尔和Goritz模型。PU纳米复合材料的非线性粘弹性行为与Maier和Goritz模型吻合得很好，该模型包括PU链在填料表面上的吸附/脱附的影响。观察到的结果强调了具有有机改性GO片的PU复合材料在电容器应用中的可能性。(C)2014爱思唯尔有限公司版权所有。
This study aims at investigating the dynamic mechanical, dielectric and rheological properties of reinforced polyurethane (PU) nanocomposites containing hydrophilic graphene oxide (GO) and/or hydrophobic modified graphene oxide (mGO) sheets. The organic modification of GO was performed with 4,4'-methylenebis (phenyl isocyanate) (MDI) and the samples were prepared by solvent mixing. We found that addition of mGO provides a more significant increase in the dielectric permittivity as compared to the addition of GO. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) spectroscopy demonstrate the more effective dispersion of thin exfoliated sheets of mGO in the PU matrix as compared to unmodified GO. This qualitative morphology observation is correlated with the quantitative results inferred from the dynamic mechanical analysis, rheology and dielectric studies. The viscoelastic Payne effect is noticed for all nanocomposites and the filler-filler and polymer-filler interactions are studied by applying the Kraus and Maier and Goritz models. The non-linear viscoelastic behavior of the PU nanocomposites is in good agreement with the Maier and Goritz model, which includes the effects of the adsorption/desorption of PU chains on the filler surface. The observed results underline the possibilities of PU composites with organically modified GO sheets in capacitor applications. (C) 2014 Elsevier Ltd. All rights reserved.