聚酯低聚物和聚乙二醇醚对蒙脱土的插层与剥离作用

高分子基 /层状硅酸盐钠米复合材料的制备得益于自然界存在的一类层状硅酸盐 .它具有阳离子可交换性和在一些介质中的可膨润性 .在层状硅酸盐中蒙脱土是使用较普遍的一种 .它的晶胞系由两层Ｓｉ—Ｏ四面体中间夹一层Ａｌ—Ｏ(ＯＨ)八面体组成 .晶胞呈平行迭置 .层内有剩余电子而使其带负电荷 ,它与层间的自由阳离子Ｎａ+、Ｋ+、Ｃａ2 +、Ｍｇ2 +等达到电荷平衡 ,保持其整体的电中性 .利用蒙脱土的阳离子可交换特性 ,将有机离子插层剂或反应单体插入ＭＭＴ层间 ,使其层间距撑大 ,并增加其在反应体系中的膨润性 ,使ＭＭＴ在反应体系中剥离 ,…

INTERCALATE AND EXFOLIATE ACTION OF BHET AND PEG FOR MONTMORILLONITE

The intercalate and exfoliate actions of BHET or PEG for montmorillonite are discussed.BHET(ethylene glycol terephthalate) can be absorbed and intercalated between layers of montmorillonite, not only at high temperature, but also normal temperture.Especially at temperatures,30～40℃ over the melt temperature,more BHET are absorbed by montmorillonite.When the content of montmorillonite is less than 10% in its mixture with BHET the stack layers of montmorillonite can be exfoliated into single layers.But when the content of montmorillonite is more than 10% a few exfoliated layers combined into more layers.Montmorillonites can also absorb PEG,but in this case only the layer distances are increased,no layer exfoliation is observed.Between the layers one to three layers of PEG molecules can be absorbed.So that,there are respectively three peaks d=4.4,3.4 and 1.8nm in WAXD curves.When the content of montmorillonite is more than 10% there is only one layer distance d=1.8nm.