基于基团贡献法和分子动力学预测聚间苯二甲酰对苯二胺的玻璃化转变温度  

Using Group Contribution Method and Molecular Dynamics to Predict the Glass Transition Temperature of Poly( p-phenylene isophthalamide)

作　　者：吴红枚[1] 李惠婷 李永成[1] 王宏青[1] 王孟[1] WU Hongmei;LI Huiting;LI Yongcheng;WANG Hongqing;WANG Meng(Department of Polymer Science and Engineering,College of Chemistry and Chemical Engineering,University of South China,Hengyang 421001,China)

机构地区：[1]南华大学化学化工学院高分子材料与工程系,衡阳421001

出　　处：《高等学校化学学报》2019年第1期180-186,共7页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金(批准号:21104031);南华大学研究生科学基金(批准号:2018KYY046)资助~~

摘　　要：采用基团贡献法(GC)和分子动力学法(MD)模拟了聚间苯二甲酰间苯二胺纤维(MPDI)和聚对苯二甲酰对苯二胺(PPTA)的玻璃化转变温度,并与实验值进行了对比.结果表明,使用基团贡献法和分子动力学法测得的MPDI和PPTA的玻璃化转变温度与实验值接近,说明基团贡献法和分子动力学法可以用来预测芳香族聚酰胺的玻璃化转变温度.在此基础上,采用GC和MD预测了聚间苯二甲酰对苯二胺(PPIA)的玻璃化转变温度.在MD模拟中,对密度、比体积、回转半径和非键相互作用随温度的变化规律进行了分析.结果表明,自由体积理论能较好地解释PPIA的玻璃化转变现象,其中非键相互作用随温度的变化是玻璃化转变的本质原因. PPIA的玻璃化转变温度介于MPDI和PPTA之间,有望成为综合性能介于两者之间的另一种高性能聚酰胺.Aramid fibers mainly include wholly aromatic polyamide and heterocyclic aromatic polyamide,while the wholly aromatic polyamides(aramids)are considered to be high-performance organic materials due to their outstanding thermal and mechanical properties.Their high-performances arise from their aromatic structure and amide linkages.The better known commercial aramids,poly(p-phenylene terephthalamide)(PPTA)and poly(m-phenylene isophthalamide)(MPDI),are used in advanced technologies and have been transformed into high-strength and flame-retardant fibers and coatings,with applications in the aerospace and armament industry.Poly(p-phenylene isophthalamide)(PPIA),a new aromatic polyamide,has not yet been commercialized and there are few reports about its comprehensive performance until nowadays.In this paper,Group Contribution(GC)method and molecular dynamics(MD)simulation were used to simulate the glass transition temperatures(T g)of MPDI and PPTA.Then analysis and comparisons of the glass transition temperatures by GC method and MD simulation with their experimental values are presented.The results show that the glass transition temperature measured by GC method and MD simulation is very close to the experimental value,and that the change of the density,specific volume,radius of gyration and energy along with temperature can cha-racterize the glass transition temperature.Then these two methods were exploited to simulate the T g of PPIA.The change of the density,specific volume,radius of gyration and energy interactions along with temperature were analyzed in the MD simulation.The results show that the free volume theory can explain the glass transition phenomenon of PPIA,and the change of the non-bond energy interactions with temperature is the essential reason.These results indicates that PPIA has the potential to become another high performance polyamide with its T g lying between those of both MPDI and PPTA.It is of great significance to emphasize on the synthesis of PPIA with sufficiently high molecular weight.In ge

关 键 词：基团贡献法 分子动力学模拟 玻璃化转变温度 聚间苯二甲酰对苯二胺 

分 类 号：O631[理学—高分子化学]