Fabrication, characterization and microwave properties of polyurethane nanocomposites reinforced with iron oxide and barium titanate nanoparticles
Fabrication, characterization and microwave properties of polyurethane nanocomposites reinforced with iron oxide and barium titanate nanoparticles
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DOI：
10.1016/j.actamat.2008.09.024
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发表时间：
2009-01-01
期刊：
影响因子：
9.4
通讯作者：
Young, D. P.
中科院分区：
文献类型：
--
作者：
Guo, Z.;Lee, S. -E.;Young, D. P.
采用表面引发聚合法制备了磁性氧化铁纳米粒子和介电钛酸钡纳米粒子增强聚氨酯（PU）纳米复合材料。掺入不同纳米颗粒的聚合物基质在纳米颗粒周围表现出不同的呈现状态，即，化学键合、物理缠结和本体聚合物链。纳米粒子对聚合物纳米复合材料的热稳定性有不同的影响。通过嵌入不同的功能纳米粒子，观察到独特的物理性质，如增大的介电常数和更大的介电常数（真实的介电常数）。探讨了二元纳米粒子增强聚氨酯纳米复合材料的协同效应。铁氧化物纳米颗粒的加入对介电常数有一定的影响。然而，在Fe 2 O3/PU纳米复合材料中引入介电钛酸钡纳米颗粒后，观察到的磁性能和磁导率的差异不大。研究了γ-Fe 2 O3和BaTiO 3纳米粒子增强聚氨酯纳米复合材料在10 MHz ~ 1 GHz频率范围内的磁导率和介电常数。由Bruggeman方程预测的材料的微波性能与实测值基本一致，但对Fe_2O_3/BaTiO_3/PU的真实的介电常数的预测值与实测值有较大差异。采用体积平均法（VAM）研究纤维增强复合材料的厚度方向增强体。用VAM法预测的真实的介电常数与实测值的符合程度比用Bruggeman方程预测的好。(C)2008 Acta Materialia Inc.由爱思唯尔有限公司出版。保留所有权利。
Polyurethane (PU) nanocomposites reinforced with magnetic iron oxide nanoparticles and/or dielectric barium titanate nanoparticles fabricated by the surface-initiated-polymerization approach were investigated. The polymer matrix incorporated with different nanoparticles shows different presenting status Surrounding the nanoparticles, i.e., chemical bonding, physical entanglement and bulk polymer chain. The nanoparticles have a different effect on the thermal stability of the polymer nanocomposites. By embedding different functional nanoparticles, unique physical properties were observed, such as enlarged coercivity and larger dielectric constant (real permittivity). The synergistic effect of the binary nanoparticle reinforced PU nanocomposite was explored. The addition of the iron oxide nanoparticles does have some effect on the permittivity. However, little difference was observed in the magnetic properties and permeability after the introduction of the dielectric barium titanate nanoparticle into Fe2O3/PU nanocomposites. The permeability and permittivity of gamma-Fe2O3 and BaTiO3 nanoparticle reinforced PU nanocomposites were investigated with frequencies ranging from 10 MHz to 1 GHz. The predicted microwave properties from Bruggeman's equation were consistent with the measured data, except for the real permittivity of Fe2O3/BaTiO3/PU. The volume average method (VAM) usually used for fiber-reinforced composites with reinforcements in the thickness direction was applied in this nanocomposite system. The predicted real permittivity by VAM was Found to be in better agreement with the measured data than that predicted by Bruggeman's equation. (C) 2008 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.