膨润土复合改性研究

Study on Composite Modification of Montmorillonite

为增加膨润土和有机物的相容性,采用无机金属阳离子,有机阴、阳离子表面活性剂对膨润土进行复合改性,研究了改性剂种类、插层次序对改性效果的影响。X-射线衍射分析表明:阳-阳离子复合改性对层间距的改变不大,先阳离子后阴离子的插层顺序有利于层间距增大(从1.04nm增大到4.14nm),此外还可利用配位作用将二次改性剂引入金属离子一次改性MMT中,使层间距增大。改性机理研究认为:阳离子改性机理为层间离子交换,而阴离子改性机理是改性剂和MMT表面形成了氢键。沉降实验表明复合改性土在有机溶剂中分散能力较一次改性土有所增强。TGA分析表明由复合改性土制备的复合材料具有较高的热稳定性。

To ensure good compatibility between polymer and inorganic phase （silicate）, a series of organo-montmorillonite （MMT） were prepared by composite modification via inorganic metal cation and/or organic cationic or anionic surfactants as intercalation agents. The influence of modifying agent style and insert method on modifying effect were studied. The results of X-ray diffraction show that the spacing of MMT layers are less increased when cation and cation inserted MMT. When the anion-cation second modified MMT, the insert order that cation insert firstly and then the anion is good to the increase of d-spacing （from 1.04 to 4.14nm）. And the result also show the metal ions which have the function of coordination modify MMT firstly, and the function of coordination could be used to import the second insert modifier to increase the d-spacing. The reaction mechanism according to the experiment results is that the cation modifying is ion exchange and the anion insert is the formation of hydrogen bond between the surface of modifier and MMT. The sedimentation experiment result shows that the complex inserted MMT have better dispersibility than first inserted MMT. The TGA result shows that the complex material which was synthesized from composite modified MMT has high thermal stability.