A combined experiment and molecular dynamics simulation study of hydrogen bonds and free volume in nitrile-butadiene rubber/hindered phenol damping mixtures
A combined experiment and molecular dynamics simulation study of hydrogen bonds and free volume in nitrile-butadiene rubber/hindered phenol damping mixtures
复制标题
丁腈橡胶/受阻酚阻尼混合物中氢键和自由体积的联合实验和分子动力学模拟研究
DOI：
10.1039/c2jm31716h
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发表时间：
2012-01-01
影响因子：
--
通讯作者：
Wu, Sizhu
中科院分区：
文献类型：
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作者：
Qiao, Bo;Zhao, Xiuying;Wu, Sizhu
通过实验和分子模拟相结合，我们系统地阐明了受阻酚（AO-80）小分子的引入导致丁腈橡胶（NBR）阻尼性能显着提高的基本机制。在分子水平上，通过FTIR、H-1-NMR和温度依赖性FTIR，观察到AO-80小分子和NBR聚合物链之间存在氢键(H-bond)相互作用，导致形成H-键网络结构。同时，利用正电子湮灭寿命谱仪（PALS）和分子动力学模拟对不同NBR/AO-80混合物的自由体积分数进行了表征，通过定量比较，其在共混质量比为100/60时达到最小值，同时具有最多的氢键数量和最大的结合能。所有这些微观分析只是合理化了最大动态损耗因子。因此，表明存在橡胶与受阻酚分子的最佳比例以实现最大阻尼性能。这些基础研究有望为设计和制造高性能聚合物阻尼材料提供一些有用的信息。
By combining experiment and molecular simulation, in this work we have systematically elucidated the fundamental mechanism of the significantly improved damping property of nitrile-butadiene rubber (NBR) contributed by the introduction of hindered phenol (AO-80) small molecules. At the molecular level, through FTIR, H-1-NMR and temperature-dependent FTIR, it is observed that hydrogen bonds (H-bonds) interaction exists between AO-80 small molecules and NBR polymer chains, leading to the formation of a H-bonds network structure. Meanwhile, positron annihilation lifetime spectrometer (PALS) and molecular dynamics simulation were also employed to characterize the fractional free volume for different NBR/AO-80 mixtures and it reached the minimum at the blending mass ratio of 100/60, which also possesses the largest number of H-bonds and the greatest binding energy through quantitative comparison. All of these microscopic analyses just rationalize the maximum dynamic loss factor. Therefore, it was indicated that there was an optimum ratio of rubber to hindered phenol molecules for achieving the maximum damping property. These fundamental studies are expected to provide some useful information to design and fabricate the high-performance polymeric damping materials.