剥离型聚苯乙烯/蒙脱土纳米复合材料的制备及表征

Preparation and Characterization of Exfoliated Polystyrene/Montmorillonite Nanocomposites

采用对氯甲基苯乙烯和十二烷基二甲基胺进行季铵化反应合成了一种新型的季铵盐。通过核磁共振氢谱（^1H-NMR）证实该季铵盐为可聚合的对乙烯苄基二甲基十二烷基氯化铵（VDAC）。用VDAC对钠基蒙脱土进行有机化处理，使蒙脱土层间距由1．25nm提高到了2．31nm。将改性后的蒙脱土分散在苯乙烯中进行原位本体插层聚合制得了纳米复合材料。X射线衍射（XRD）和透射电镜（TEM）测试表明在蒙脱土含量为3％～10％范围内时以剥离状态分散在聚苯乙烯基体中。差示扫描量热（DSC）分析表明聚苯乙烯／蒙脱土纳米复合材料的玻璃化转变温度随着蒙脱土含量的升高而提高。

A polymerizable quaternary ammonium salt, vinylbenzyldimethyldodecylammonium chloride （VDAC） was synthesized by the reaction of p-chloromethyl styrene （CMS） and dimethyldodecylarnine and characterized by ^1H-NMR. Organophilic montmorillonite （O--MMT） was prepared by cationic exchange between inorganic ions of MMT and ammonium cations of VDAC in an aqueous medium and the layer spacing increased from 1.25 nm to 2. 31 nm. Polystyrene- clay nanocomposites were prepared by free radical bulk polymerization of styrene containing dispersed organophilic MMT. Exfoliation of MMT in polystyrene matrix was achieved as revealed by X-ray diffraction （XRD） and transmission electron microscopy （TEM）. The glass transition temperature of polystyrene matrix increased with the increasing of MMT loading.