Molecular simulations of gas transport in nitrile rubber and styrene butadiene rubber
Molecular simulations of gas transport in nitrile rubber and styrene butadiene rubber
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DOI：
10.1016/j.polymer.2006.08.062
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发表时间：
2006-10-18
期刊：
影响因子：
4.6
通讯作者：
Doruker, Pemra
中科院分区：
文献类型：
--
作者：
Kucukpinar, Esra;Doruker, Pemra
丁腈橡胶（NBR，39：61重量%的丙烯腈：丁二烯）和苯乙烯丁二烯橡胶（SBR，50：50重量%的苯乙烯：丁二烯）基质已经通过分子动力学（MD）模拟平衡。过渡态方法被用来计算这些矩阵中的小的助溶剂的扩散和溶解系数，在NBR和合理的协议与实验结果表明相当低的值。已经进行了MD模拟来分析这些矩阵中的水扩散。水分子的聚集在疏水基质SBR中观察到。MD模拟与虚构的非极性水分子抑制聚集，并导致增强扩散SBR。在NBR中，虚拟水分子的扩散略有增加。NBR中较低的扩散常数是由于更紧密的分子间堆积和更高的内聚能密度导致基质的局部松弛较慢。影响溶解度系数的自由体积分布不是这些基质中扩散系数的主要决定因素。(c)2006爱思唯尔有限公司版权所有。
Nitrile rubber (NBR, 39:61 wt% of acrylonitrile:butadiene) and styrene butadiene rubber (SBR, 50:50 wt% of styrene: butadiene) matrices have been equilibrated by molecular dynamics (MD) simulations. Transition-state approach is used to calculate the diffusion and solubility coefficients of small penetrants in these matrices, indicating quite low values in NBR and reasonable agreement with experimental results. MD simulations have been performed to analyze water diffusion in these matrices. Aggregation of water molecules is observed in the hydrophobic matrix SBR. MD simulations with fictitious nonpolar water molecules inhibit aggregation and lead to enhanced diffusion in SBR. In NBR there is a slight increase in diffusion for fictitious water molecules. The lower diffusion constants in NBR result from slower local relaxation of the matrix due to tighter intermolecular packing and higher cohesive energy density. The free volume distribution that affects solubility coefficients is not a major determining factor for the diffusion coefficients in these matrices. (c) 2006 Elsevier Ltd. All rights reserved.