摘要
用FTIR和WAXD法研究了甲苯 2 ,4 二异氰酸酯 (TDI)的邻位和对位异氰酸酯基团与蒙脱土表面羟基的修饰反应 ,在此基础上提出了结构模型 ;用TDI修饰后的蒙脱土成功制备了插层型聚苯乙烯 /蒙脱土纳米复合材料 ,并用WAXD和TEM进行了表征 .实验结果表明 ,修饰后TDI与蒙脱土表面形成化学键 ,使蒙脱土的片层间距显著增大 ,十六烷基三甲基溴化铵 (CTAB)在蒙脱土层间由双层平行排列转变为双层脂肪链倾斜方式排列 .在苯乙烯插层聚合过程中 ,蒙脱土层间距进一步扩大 ,其初级粒子在聚苯乙烯基体中的厚度约2 0～ 5 0nm .
Fourier Transform Infrared (FTIR) Spectroscopy and Wide Angle X\|ray Diffraction (WAXD) techniques were used to study a selective modification of montmorillonite with hydroxyl group (—OH) of toluene\|2,4\|di\|isocyanate (TDI).Based on the investigation results,a schematic model was presented.The selective modification product was applied to prepare an intercalated polystyrene/montmorillonite nanocomposite,and the nanocomposite was characterized by WAXD and Transmission Electron Microscopic (TEM) techniques.The FTIR results showed that after modification of cetyltrimethylammonium bromide (CTAB) exchanged montmorillonite,TDI was successfully selectively grafted to the surface —OH group of the montmorillonite via two different synthetic routes.And the WAXD results revealed that the interlayer distance of the montmorillonite was increased dramatically.Combining with the previous investigations,it may be deduced that the orientation of the CTAB might be changed from a bilayer structure parallel to adjacent silicate layers in CTAB\|exchanged montmorillonite to a double layer inclined structure in the interlayer space of the TDI grafted montmorillonite product.The TDI modified montmorillonite product could be successfully applied to obtain an intercalated polystyrene/montmorillonite nanocomposite.During the intercalative polymerization process,the interlayer distance of the TDI modified montmorillonite was increased further.Five sharp diffraction peaks, d 001 =4.24,4.60,5.07,6.59,7.48nm,appeared for the polystyrene/TDI modified montmorillonite nanocomposite.The TEM investigation indicated that the thickness of the montmorillonite primary particles was reduced to 20～50nm in the polystyrene matrix.The WAXD and TEM results suggested that an intercalated polystyrene/TDI modified montmorillonite nanocomposite was successfully achieved.
出处
《高分子学报》
SCIE
CAS
CSCD
北大核心
2000年第5期599-603,共5页
Acta Polymerica Sinica
基金
国家自然科学基金重点基金资助项目!(基金号59833310)
