分子动力学模拟研究聚乳酸/聚酰胺11共混物的相容性  

Molecular dynamics simulations for miscibility of PLA/PA11 blends

作　　者：廖黎琼[1,2] 付一政[1,2] 梁晓艳[1,2] 梅林玉[1,2] 刘亚青[1,2] 

机构地区：[1]中北大学山西省高分子复合材料工程技术研究中心,山西太原030051 [2]中北大学材料科学与工程学院,山西太原030051

出　　处：《分子科学学报》2012年第6期506-511,共6页Journal of Molecular Science

基　　金：山西省青年科技研究基金资助项目(2010021023-5);山西省研究生优秀创新项目(100115127)

摘　　要：采用分子动力学(MD)模拟方法在COMPASS力场下,研究了不同质量比(10/90,30/70,50/50,70/30和90/10)聚乳酸(PLA)/聚酰胺11(PA11)共混物的相容性.研究结果表明:不同比例下PLA/PA11共混物的Gibbs自由能变化均大于零,其共混物很难形成均相体系;共混体系结合能的计算以及不同组分分子间C—C原子对径向分布函数的分析揭示了PLA和PA11的相互作用主要源自其分子间的范德华力;此外,模拟得到的所有比例下共混物的Flory-Huggins相互作用参数(χ)均大于临界Flory-Huggins相互作用参数(χcritical),进一步证明PLA与PA11不能形成相容体系。The objective of this study was to develop a computational model based on atomistic molecular dynamics（MD） simulations technique to investigate the miscibility of polylactic acid（PLA）/polyamide11（PA11） blends by using the COMPASS force-field.Five PLA/PA11 blends（with the weight ratio at 10/90,30/70,50/50,70/30 and 90/10） were examined.It is found that all the Gibbs free energies of different compositions PLA/PA11 blends are positive,indicating the immiscibility of PLA/PA11 blends.The van der Waals interaction is the dominating force between PLA and PA11 polymers by calculating the binding energy of PLA/PA11 blends and analysing the radial distribution function of the inter-molecular carbon-carbon atom pairs of the different compositions PLA/PA11 blends.Furthermore,all the calculated Flory-Huggins interaction parameters are all above the critical Flory-Huggins interaction parameter value,which further means that the PLA is immiscible with PA11 over the entire composition range.

关 键 词：PLA PA11 结合能 相互作用参数 径向分布函数 

分 类 号：O641[理学—物理化学]