Dynamics of Precise Ethylene Ionomers Containing Ionic Liquid Functionality
Dynamics of Precise Ethylene Ionomers Containing Ionic Liquid Functionality
复制标题
含有离子液体功能的精确乙烯离聚物的动力学
DOI：
10.1021/ma502168e
复制
发表时间：
2015
期刊：
影响因子：
5.5
通讯作者：
J. Runt
中科院分区：
文献类型：
--
作者：
U. Choi;L. R. Middleton;M. Soccio;C. F. Buitrago;Brian S. Aitken;Hanqing Masser;K. Wagener;K. Winey;J. Runt
本文首次报道了新型线型和精确官能化乙烯共聚物的分子动力学研究结果。具体地说，我们利用宽带介电弛豫谱来研究线性聚乙烯(PE)离聚体的分子动力学，这些离聚体恰好在每9个、15个或21个碳原子上含有1-甲基咪唑溴(ImBr)侧基，以及一个伪随机类似物。我们还使用FTIR光谱来洞察局部离子相互作用和侧基之间乙烯间隔物有序性的本质。先前的X射线散射实验表明，这些离聚体中的极性离子基团自组装成分散在非极性PE基质中的微相分离聚集体。我们主要关注节段性松弛的动力学，由于离子聚集，与线性PE相比，节段性松弛显著减慢。弛豫时间取决于组成、结晶度和微相的存在。
This paper presents the first findings on the molecular dynamics of the remarkable new class of linear and precisely functionalized ethylene copolymers. Specifically, we utilize broadband dielectric relaxation spectroscopy to investigate the molecular dynamics of linear polyethylene (PE)-based ionomers containing 1-methylimidazolium bromide (ImBr) pendants on exactly every 9th, 15th, or 21st carbon atom, along with one pseudorandom analogue. We also employed FTIR spectroscopy to provide insight into local ionic interactions and the nature of the ordering of the ethylene spacers between pendants. Prior X-ray scattering experiments revealed that the polar ionic groups in these ionomers self-assemble into microphase-separated aggregates dispersed throughout the nonpolar PE matrix. We focus primarily on the dynamics of the segmental relaxations, which are significantly slowed down compared to linear PE due to ion aggregation. Relaxation times depend on composition, the presence of crystallinity, and microphas...