基于胶束插层方法制备高热稳定性和大层间距有机化蒙脱土

采用不同方法制备了多种有机化蒙脱土,并分别采用X射线衍射仪、红外光谱分析仪、热重分析仪、电感耦合等离子体发射光谱仪、元素分析仪、扫描电子显微镜对产物进行了表征,并提出了有机物插层新方式——胶束插层.结果表明:适量钠基蒙脱土(Na-MMT)、十六烷基三甲基溴化铵(CTAB)和磷酸三苯酯(TPP)在丙酮/水的混合溶剂中进行溶液插层,得到的有机化蒙脱土具有更大的层间距,比单纯采用CTAB的插层效果显著.产物中含有约21.54%的CTAB和17.47±1.05%的TPP,插层机理为CTAB-TPP胶束插层.该有机化蒙脱土的初始热降解温度比单纯CTAB插层蒙脱土最多提高了17.4℃.采用该方法制备的改性蒙脱土既可以进一步提高蒙脱土的层间距,又可以封闭TPP于MMT的片层间,阻止TPP挥发;同时克服季铵盐改性蒙脱土的热稳定性低的问题,得到了层间距大、热稳定性高的有机化蒙脱土,为有机化蒙脱土在高熔点聚合物改性方面提供了条件.

Preparation of the organic montmorillonite with higher thermalstability and larger layer-spacing via micelle intercalation mechanism

The organic-montmorillonite（OMMT） modified by Triphenyl phosphate（TPP） and cetyltrimethylammonium bromide（CTAB） was prepared by using different methods,and their properties were characterized by using X-ray diffraction（XRD）,Fourier transform infrared spectroscopy（FTIR）,optical microscopy（OM）,thermalgravimetric analysis（TGA）,Elemental analysis,inductively coupled plasma-optical emission spectrometer（ICP-OES） method and Scanning electron microscopy（SEM）,respectively.The results suggest that in mixed solvents of acetone/H2O,the appropriate amount of CTAB and TPP can form micelle and insert into the layer of MMT,and the resulting organic-montmorillonite named of T-MMT has larger layer spacing than those simply prepared by using CTAB intercalation（C-MMT）.The results prove that the product has about 21.54% of CTAB and 17.47±1.05% of TPP in MMT,and its initial thermal degradation temperature is about 17.4 ℃ higher than the traditional C-MMT.The organic MMT prepared by this method can not only enhance the MMT layer spacing,but also prevent the evaporation of TPP.T-MMT overcomes the problem of low thermal stability of the quaternary ammonium modified montmorillonite,and it can be used in modifying the engineering plastics that has a high thermal-processing temperature.