Ⅳ型储氢气瓶内衬材料聚酰胺6氢渗透行为的分子模拟研究  

Molecular simulation of hydrogen permeation behavior of polyamide 6 liner material for type IV hydrogen storage cylinder

作　　者：张学敏[1] 翟丽珍 李厚补 齐国权 黄尚彬 张冬娜 杨志锋 张晓宇 ZHANG Xuemin;ZHAI Lizhen;LI Houbu;QI Guoquan;HUANG Shangbin;ZHANG Dongna;YANG Zhifeng;ZHANG Xiaoyu(School of Materials Science and Engineering,Chang'an University,Xi'an 710064,China;State key Laboratory for Performance and Structure Safety of Petroleum Tubular Goods and Equipment Materials,CNPC Tubular Goods Research Institute,Xi'an 710077,China;Baoji Tianlian Huitong Composite Material Co.Ltd,Baoji 712013,China)

机构地区：[1]长安大学材料科学与工程学院,西安710064 [2]中国石油集团工程材料研究院有限公司,石油管材及装备材料服役行为与结构安全国家重点实验室,西安710077 [3]宝鸡天联汇通复合材料有限公司,陕西宝鸡712013

出　　处：《中国塑料》2024年第8期62-68,共7页China Plastics

基　　金：国家自然科学基金面上项目(52274069);陕西省重点研发计划(2023-YBGY-177);大学生创新创业训练计划项目(X202210710582)。

摘　　要：采用分子模拟方法,在不同温度(30、40、60、80℃)和压力(82、87.5、98、103 MPa)条件下,研究氢气在聚合物材料聚酰胺6(PA6)中的渗透性,并分析了氢气的渗透机理。结果表明,温度升高时,吸附热和自由体积分数逐渐增加,热运动加剧,分子运动空间增大,氢气在PA6中的溶解度系数、扩散系数以及渗透系数均呈增大趋势。在压力为103 MPa时,升高温度对渗透系数的影响最大,增加了88.3%。随着压力增大,氢气与PA6分子链之间的相互作用减小,自由体积分数减小,所以氢气在PA6中的溶解度系数、扩散系数以及渗透系数均呈下降趋势。在温度为60℃时,压力对渗透系数影响最显著,降低了38.6%。氢气在PA6中的渗透机理包括在低势能区的聚集性吸附过程,和在自由体积处形成的空穴内振动-空穴间跃迁的扩散过程,温度升高时,氢气分子运动变得活跃,有更多的空穴间跳跃次数,压力升高时,变化相反。In this work,the permeability of hydrogen in the polymer polyamide 6(PA6)was studied by molecular simula⁃tion methods at different temperatures(30,40,60 and 80℃)and pressures(82,87.5,98 and 103 MPa).Meanwhile,the permeability mechanism of hydrogen was analyzed.The results indicated that as the temperature increases,the ad⁃sorption heat and free volume fraction gradually increases,the thermal motion intensifies and the molecular motion space increases.And the solubility,diffusion and permeability coefficient of hydrogen in PA6 all increase.At a pressure of 103 MPa,increasing the temperature has the greatest impact on the permeability coefficient,which increases by 88.3%.With the increase of pressure,the interaction between hydrogen and PA6 molecular chains decreases and the free volume fraction decreases,so the solubility,diffusion and permeability coefficient of hydrogen in PA6 all show a downward trend.When the temperature was 60℃,the pressure had the most significant influence on the permeability coefficient,which de⁃creased by 38.6%.The permeation mechanism of hydrogen in PA6 includes the aggregation adsorption process in the low potential energy region and the diffusion process of intra⁃cavity vibration⁃inter⁃cavity transition formed in the free vol⁃ume.With the increase of temperature,the movement of hydrogen molecules becomes active and there are more inter⁃cavity jumps.When the pressure increases,the change is opposite.

关 键 词：聚酰胺6 氢气 扩散 吸附 渗透 分子模拟 

分 类 号：TQ320.2[化学工程—合成树脂塑料工业]