Molecular dynamics simulation of cross-linked epoxy resin and its interaction energy with graphene under two typical force fields
Molecular dynamics simulation of cross-linked epoxy resin and its interaction energy with graphene under two typical force fields
复制标题
两种典型力场下交联环氧树脂的分子动力学模拟及其与石墨烯的相互作用能
DOI：
10.1016/j.commatsci.2017.11.007
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发表时间：
2018-02-15
影响因子：
3.3
通讯作者：
Du, Xiaoze
中科院分区：
文献类型：
--
作者：
Sun, Yingying;Chen, Lin;Du, Xiaoze
建立了由双酚A树脂、2,3,6-四氢-3-甲基邻苯二酸酐固化剂和2,4,6-三（二甲氨基甲基）苯酚促进剂组成的交联环氧树脂体系模型，并进行了分子动力学模拟，计算了环氧树脂及其复合材料的性能。结果表明，采用dreding力场计算得到的均方位移（MSD）和玻璃化转变温度（T-g）均小于PCFF力场计算得到的结果，且dreding力场的模拟结果与实验结果吻合较好。随着模拟规模的增大，总MSD增大，而T-g略有减小。当DGEBA大于12时，模拟系统的T-g值与实验相近。环氧树脂体系的分子运动也受交联度的影响，未交联颗粒的存在增加了总MSD。在石墨烯/环氧复合材料中，改性单层石墨烯（MMG）片材之间的相互作用能大于环氧树脂与石墨烯之间的相互作用能，表明改性单层石墨烯片材在与环氧树脂混合时容易团聚。石墨烯的功能化可以降低MMG片材之间的相互作用能，提高环氧树脂与石墨烯之间的相互作用能，有利于石墨烯的分散。(C) 2017 Elsevier b.v.版权所有
A model of cross-linked epoxy system composed of bisphenol-A resin, 2,3,6-tetrahydro-3-methylphthalic anhydride curing agent, and 2,4,6-tris(dimethylaminomethyl) phenol accelerator was established and molecular dynamics simulations were performed to calculate the properties of the epoxy and its composites. The results show that the mean square displacement (MSD) and glass transition temperature (T-g) calculated by Dreiding force field are always lower than that by PCFF force field, and the simulation results of Dreiding force field are better consistent with experiments. With the increasing simulation size, total MSD increases while T-g decreases slightly. The simulated systems with DGEBA more than 12 have T-g values similar to experiments. The molecular motion of epoxy system is also influenced by the crosslinking degree, and the presence of uncross-linked particles increases the total MSD. In the graphene/epoxy composites, interaction energy between modified monolayer graphene (MMG) sheets is larger than that between epoxy and graphene, indicating that MMG sheets tend to agglomerate when mixing with epoxy. Functionalization of graphene can reduce interaction energy between MMG sheets and increase that between epoxy resin and graphene, which is beneficial to the dispersion of graphene. (C) 2017 Elsevier B. V. All rights reserved.