中国塑料 ›› 2022, Vol. 36 ›› Issue (2): 67-74.DOI: 10.19491/j.issn.1001-9278.2022.02.011

• 加工与应用 • 上一篇    下一篇

改性剂及高密度聚乙烯插层和剥离蒙脱石的分子动力学模拟

李永青, 杨小龙, 陈文静, 闫晓堃, 马秀清()   

  1. 北京化工大学机电工程学院,北京 100029
  • 收稿日期:2021-07-01 出版日期:2022-02-26 发布日期:2022-02-23
  • 通讯作者: 马秀清(1966—),女,教授,从事高分子材料改性研究,maxq@mail.buct.edu.cn
    E-mail:maxq@mail.buct.edu.cn
  • 基金资助:
    大容量塑料内胆可靠性设计技术、可控成型与焊接工艺研究(2020YFB1506102)

Molecular dynamics simulation of modifier and high⁃density polyethylene intercalate and exfoliate montmorillonite

LI Yongqing, YANG Xiaolong, CHEN Wenjing, YAN Xiaokun, MA Xiuqing()   

  1. School of Mechanical and Electrical Engineering,Beijing University of Chemical Technology,Beijing 100029,China
  • Received:2021-07-01 Online:2022-02-26 Published:2022-02-23
  • Contact: MA Xiuqing E-mail:maxq@mail.buct.edu.cn

摘要:

为研究高密度聚乙烯/有机改性蒙脱石(PE?HD/OMMT)复合材料中改性剂及PE?HD对蒙脱石(MMT)插层和剥离的影响,采用分子动力学方法模拟了OMMT中不同负载量的十八烷基三甲基氯化铵阳离子(OTAC+)在MMT中的排列方式以及对MMT插层的影响。此外,搭建了PE?HD/OMMT复合材料模型,编写MS Perl脚本提取了OTAC+与MMT和PE?HD之间的相互作用能来研究双螺杆挤出机机筒温度在463 K下对MMT剥离的影响。模拟结果表明,随着OTAC+负载量的提高,其在MMT片层中依次呈现为单层分布、双层分布和假三层分布;同时,OTAC+负载量的增加致使MMT的层间距有所增加,但MMT并未发生剥离;模拟时间在90~95 ps内时,PE?HD/OMMT复合材料模型中顶层和底层MMT间的相互作用能由-24.53 kcal/mol转变为3.54 kcal/mol,说明MMT发生了剥离,此时MMT的层间距为91 ?。

关键词: 分子动力学, 模拟, 改性剂, 高密度聚乙烯, 蒙脱石, 插层, 剥离

Abstract:

To study the effects of modifiers and high?density polyethylene (PE?HD)/organo?modified montmorillonite (OMMT) composites on the intercalation and exfoliation of montmorillonite, a molecular dynamics method was employed to simulate the arrangement of different loadings of octadecyl trimethyl ammonium chloride cations (OTAC+) in the montmorillonite (MMT) and its influence on the intercalation of OMMT. A material model for the PE?HD/OMMT composites was constructed, and the MS Perl script was written to extract the interaction energy among OTAC+, MMT and PE?HD to study the effect of the barrel temperature of the twin?screw extruder on the exfoliation of MMT at 463 K. The simulation results indicated that the MMT slices appeared as lateral?monolayer, lateral?bilayer, and pseudotrilayer in sequence with an increase in the loading of OTAC+. Meanwhile, the increase of the OTAC+ loading resulted in an increase in the layer spacing of MMT, and however MMT was not exfoliated. In the simulation time of 90~95 ps, the interaction energy between the top and bottom of MMT in the PE?HD/OMMT composite model varied from -24.53 to 3.54 kcal/mol, indicating the successful exfoliation of MMT, leading to an MMT layer spacing of 91 ? at that time.

Key words: molecular dynamics, simulation, modifier, high?density polyethylene, montmorillonite, intercalation, exfoliation

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