Tan JingHua, Chen Chenliang, Liu Yiwu, Wu Juying, Wu Ding, Zhang Xiang, He Xiaoye, She Zhihong, He Ren, Zhang Hailiang
Key Laboratory of Advanced Packaging Materials and Technology of Hunan Province, School of Packaging and Materials Engineering, Hunan University of Technology Zhuzhou 412007 P. R. China
Institute of Systems and Engineering, China Academy of Engineering Physics Mianyang 621000 P. R. China.
RSC Adv. 2020 Mar 27;10(21):12475-12484. doi: 10.1039/d0ra00192a. eCollection 2020 Mar 24.
Diffusion and sorption of five gases (H, N, O, CO, CH) in hydrogenated nitrile butadiene rubber (HNBR) and ethylene-propylene-diene rubber (EPDM) have been investigated by molecular dynamics (MD) and grand canonical Monte Carlo (GCMC) simulations. The diffusion coefficients of gas molecules in HNBR and EPDM are well correlated with the effective penetrant diameter except for CO. CO shows a lower diffusion coefficient due to its linear shape. Additionally, the favorable interaction between CO and HNBR is another factor for its lower diffusion coefficient in HNBR. HNBR shows lower diffusion coefficients than EPDM. This is because the polar -CN groups in HNBR chains increase interchain cohesion and result in tight intermolecular packing, low free volume and poor chain mobility, which decreases the diffusion coefficients of HNBR. The solubility coefficients of CH, O, N and H in HNBR are lower than those in EPDM, which is a result of the weak HNBR-penetrant interactions and low free volume of HNBR. However, the solubility coefficient of CO in HNBR is higher than in EPDM. This is attributed to the strong interaction between CO and HNBR. H, O, N and CH show lower permeability coefficients in HNBR than in EPDM, while CO has higher permeability coefficients in HNBR. These molecular details provide critical information for the understanding of structures and gas transport between HNBR and EPDM.
通过分子动力学（MD）和巨正则蒙特卡罗（GCMC）模拟研究了五种气体（H、N、O、CO、CH）在氢化丁腈橡胶（HNBR）和乙丙三元橡胶（EPDM）中的扩散和吸附。除CO外，气体分子在HNBR和EPDM中的扩散系数与有效渗透剂直径具有良好的相关性。由于其线性形状，CO的扩散系数较低。此外，CO与HNBR之间的良好相互作用是其在HNBR中扩散系数较低的另一个因素。HNBR的扩散系数低于EPDM。这是因为HNBR链中的极性-CN基团增加了链间内聚力，导致分子间堆积紧密、自由体积低且链流动性差，从而降低了HNBR的扩散系数。CH、O、N和H在HNBR中的溶解度系数低于在EPDM中的溶解度系数，这是由于HNBR与渗透剂之间的相互作用较弱以及HNBR的自由体积较低。然而，CO在HNBR中的溶解度系数高于在EPDM中的溶解度系数。这归因于CO与HNBR之间的强相互作用。H、O、N和CH在HNBR中的渗透系数低于在EPDM中的渗透系数，而CO在HNBR中的渗透系数较高。这些分子细节为理解HNBR和EPDM之间的结构和气体传输提供了关键信息。
