The role of interfacial chemistry and interactions in the dynamics of thermosetting polyurethane–multiwalled carbon nanotube composites at low filler contents
The role of interfacial chemistry and interactions in the dynamics of thermosetting polyurethane–multiwalled carbon nanotube composites at low filler contents
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DOI：
10.1007/s00396-012-2745-4
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发表时间：
2013-03
影响因子：
2.4
通讯作者：
L. Karabanova;R. Whitby;V. Bershtein;A. Korobeinyk;P. Yakushev;O. Bondaruk;A. Lloyd;S. Mikhalovsky-S.-Mikhalov
中科院分区：
文献类型：
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作者：
L. Karabanova;R. Whitby;V. Bershtein;A. Korobeinyk;P. Yakushev;O. Bondaruk;A. Lloyd;S. Mikhalovsky-S.-Mikhalov
通过货车德瓦尔斯相互作用或共价相互作用将酸氧化的多壁碳纳米管（MWCNTs）引入到聚氨酯（PU）基体中，并利用动态力学分析和激光干涉蠕变速率谱研究了MWCNTs的玻璃化转变动力学。纳米复合材料揭示了PU玻璃化转变动力学，这取决于纳米管的含量和类型的界面相互作用的实质性影响。记录了在覆盖200 °C范围的玻璃化转变内的显著动态不均匀性和从约0至80-140 °C的主要PU松弛最大值的位移。结果被处理的框架内的化学不均匀性，约束动力学效应，和不同的运动cooperativities。复合材料中的玻璃化转变动力学的特性反映在它们的动态和静态机械性能中，特别是MWCNTs与PU的共价界面相互作用的模量和拉伸强度增加了两到三倍。
Acid-oxidized multiwalled carbon nanotubes (MWCNTs) were introduced into a polyurethane (PU) matrix at low filler levels (0.01–0.25 wt%) through either van der Waals or covalent interactions, and their glass transition dynamics using dynamic mechanical analysis and laser-interferometric creep rate spectroscopy was investigated. The nanocomposites reveal substantial impact on the PU glass transition dynamics, which depends on the nanotube content and type of interfacial interactions. The pronounced dynamic heterogeneity within the glass transition covering 200 °C range and the displacement of main PU relaxation maxima from around 0 to 80–140 °C were registered. The results are treated in the framework of chemical inhomogeneity, constrained dynamics effects, and different motional cooperativities. The peculiariaties of the glass transition dynamics in the composites are reflected in their dynamic and static mechanical properties, in particular a two- to threefold increase in modulus and tensile strength for the covalent interfacial interaction of MWCNTs with PU.