Thermal Degradation Chemistry of Alkyl Quaternary Ammonium Montmorillonite
Thermal Degradation Chemistry of Alkyl Quaternary Ammonium Montmorillonite
复制标题
DOI：
10.1021/cm010305s
复制
发表时间：
2001-08
影响因子：
8.6
通讯作者：
W. Xie;Zongming Gao;W. Pan;D. Hunter;A. Singh;R. Vaia
中科院分区：
文献类型：
--
作者：
W. Xie;Zongming Gao;W. Pan;D. Hunter;A. Singh;R. Vaia
有机改性层状硅酸盐（OLS）的热稳定性在聚合物-层状硅酸盐（PLS）纳米复合材料的制备和加工中起着关键作用。采用常规和高分辨率TGA结合傅里叶变换红外光谱和质谱（TG-FTIR-MS）和热解/GC-MS研究了蒙脱土和烷基季铵改性蒙脱土的非氧化热降解。这些OLS分解的起始温度通过TGA为约155 °C，通过TGA-MS为约180 °C，其中TGA-MS能够区分水解吸与真正的有机分解。产物分析（GC-MS）表明，OLS中表面活性剂的初始降解遵循霍夫曼消除反应，并且结构（三甲基或二甲基）、链长、表面活性剂混合物、交换比或预处理（洗涤）不会改变初始起始温度。铝硅酸盐层上的催化位点降低了热稳定性。
The thermal stability of organically modified layered silicate (OLS) plays a key role in the synthesis and processing of polymer-layered silicate (PLS) nanocomposites. The nonoxidative thermal degradation of montmorillonite and alkyl quaternary ammonium-modified montmorillonite were examined using conventional and high-resolution TGA combined with Fourier transform infrared spectroscopy and mass spectrometry (TG−FTIR−MS) and pyrolysis/GC−MS. The onset temperature of decomposition of these OLSs was approximately 155 °C via TGA and 180 °C via TGA−MS, where TGA−MS enables the differentiation of water desorbtion from true organic decomposition. Analysis of products (GC−MS) indicates that the initial degradation of the surfactant in the OLS follows a Hoffmann elimination reaction and that the architecture (trimethyl or dimethyl), chain length, surfactant mixture, exchanged ratio, or preconditioning (washing) does not alter the initial onset temperatures. Catalytic sites on the aluminosilicate layer reduce ther...