Solid-state NMR characterization of unsaturated polyester thermoset blends containing PEO-PPO-PEO block copolymers
Solid-state NMR characterization of unsaturated polyester thermoset blends containing PEO-PPO-PEO block copolymers
复制标题
含有 PEO-PPO-PEO 嵌段共聚物的不饱和聚酯热固性共混物的固态 NMR 表征
DOI：
10.1016/j.polymer.2008.04.042
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发表时间：
2008-06-10
期刊：
影响因子：
4.6
通讯作者：
Ding, Datong
中科院分区：
文献类型：
--
作者：
Li, Xinjuan;Fu, Weigui;Ding, Datong
首先，改进了我们之前工作中提出的核磁共振方法，以更准确地测量多相聚合物中的界面厚度。然后将改进的方法与其他技术相结合，应用于阐明不饱和聚酯树脂（UPR）和两亲性聚环氧乙烷-嵌段-聚环氧丙烷-嵌段-聚环氧乙烷（PEO-PPO=PEO）三嵌段共聚物热固性共混物中的相行为、混溶性、非均相动力学和微域结构。将实验结果与环氧树脂（ER）/PEO-PPO-PEO共混物进行比较，系统地阐明了二元聚合物-聚合物相互作用对具有相同PEO-PPO-PEO三嵌段共聚物的UPR和ER热固性共混物的相行为、域尺寸，特别是界面厚度的影响。结果发现，UPR/PEO-PPO-PEO表现出强烈的相分离，界面相当小，并且只有一小部分PEO与UPR混合。而ER/PEO-PPO-PEO相分离较弱，界面较厚，大量PEO与ER充分混合。研究表明，嵌段共聚物和交联热固性树脂之间的热力学相互作用是控制这些共混物中相行为、区域尺寸和界面厚度的关键因素之一。这些 NMR 结果在质量上与先前对两种不混溶聚合物之间的界面性质的理论预测非常一致。我们的 NMR 适用于具有弱和强微相分离的不同热固性共混体系，清楚地表明改进的 NMR 方法是一种通用且有用的方法，用于测量界面厚度并阐明具有可检测的异质动力学的多相聚合物中的相行为和微妙的微域结构。 (C) 2008 Elsevier Ltd. 保留所有权利。
First, the NMR method proposed in our previous work was improved to provide more accurate measurement of interphase thickness in multiphase polymers. Then the improved method, in combination with other techniques, was applied to elucidate the phase behavior, miscibility, heterogeneous dynamics and microdomain structure in thermoset blends of unsaturated polyester resin (UPR) and amphiphilic poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide) (PEO-PPO=PEO) triblock copolymer. The experimental results were compared with those of epoxy resin (ER)/PEO-PPO-PEO blends to systematically elucidate the influence of binary polymer-polymer interaction on the phase behavior, domain size and especially the interphase thickness in thermoset blends of UPR and ER, respectively, with the same PEO-PPO-PEO triblock copolymer. It was found that UPR/PEO-PPO-PEO exhibits strong phase separation with considerably small interphase, and only a small fraction of PEO is mixed with UPR. Whereas ER/PEO-PPO-PEO exhibits weak phase separation with thick interphase, and a large amount of PEO is intimately mixed with ER. It was suggested that the thermodynamic interaction between the block copolymer and cross-linked thermoset resin is one of the key factors in controlling the phase behavior, domain size and interphase thickness in these blends. These NMR results are qualitatively in good agreement with the previous theoretical prediction of interphase properties between two immiscible polymers. Our NMR works on different thermoset blend systems with weak and strong microphase separations clearly demonstrate that the improved NMR method is a general and useful method for measuring the interphase thickness and elucidating the phase behavior and subtle microdomain structure in multiphase polymers with detectable heterogeneous dynamics. (C) 2008 Elsevier Ltd. All rights reserved.