Molinari N, Khawaja M, Sutton A P, Mostofi A A
Department of Physics and ‡Department of Materials, and the Thomas Young Centre for Theory and Simulation of Materials, Imperial College London , London SW7 2AZ, U.K.
J Phys Chem B. 2016 Dec 15;120(49):12700-12707. doi: 10.1021/acs.jpcb.6b07841. Epub 2016 Dec 5.
We introduce a chemically inspired, all-atom model of hydrogenated nitrile butadiene rubber (HNBR) and assess its performance by computing the mass density and glass-transition temperature as a function of cross-link density in the structure. Our HNBR structures are created by a procedure that mimics the real process used to produce HNBR, that is, saturation of the carbon-carbon double bonds in NBR, either by hydrogenation or by cross-linking. The atomic interactions are described by the all-atom "Optimized Potentials for Liquid Simulations" (OPLS-AA). In this paper, first, we assess the use of OPLS-AA in our models, especially using NBR bulk properties, and second, we evaluate the validity of the proposed model for HNBR by investigating mass density and glass transition as a function of the tunable cross-link density. Experimental densities are reproduced within 3% for both elastomers, and qualitatively correct trends in the glass-transition temperature as a function of monomer composition and cross-link density are obtained.
我们引入了一种受化学启发的氢化丁腈橡胶（HNBR）全原子模型，并通过计算质量密度和玻璃化转变温度作为结构中交联密度的函数来评估其性能。我们的HNBR结构是通过模仿生产HNBR的实际过程创建的，即通过氢化或交联使丁腈橡胶（NBR）中的碳 - 碳双键饱和。原子间相互作用由全原子“液体模拟优化势”（OPLS - AA）描述。在本文中，首先，我们评估OPLS - AA在我们模型中的使用，特别是利用NBR的本体性质；其次，我们通过研究质量密度和玻璃化转变作为可调交联密度的函数来评估所提出的HNBR模型的有效性。两种弹性体的实验密度均在3%的误差范围内重现，并且获得了玻璃化转变温度随单体组成和交联密度变化的定性正确趋势。
