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91Å。
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 to3.54 kcal/mol,indicating the successful exfoliation of MMT,leading to an MMT layer spacing of 91Åat that time.
作者
李永青
杨小龙
陈文静
闫晓堃
马秀清
LI Yongqing;YANG Xiaolong;CHEN Wenjing;YAN Xiaokun;MA Xiuqing(School of Mechanical and Electrical Engineering,Beijing University of Chemical Technology,Beijing 100029,China)
出处
《中国塑料》
CAS
CSCD
北大核心
2022年第2期67-74,共8页
China Plastics
基金
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)。
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
moleculardynamics
simulation
modifier
high-densitypolyethylene
montmorillonite
intercalation
exfoliation
