Zhou Yi, Liu Qinghe, Xu Peijie, Cheng Hongfei, Liu Qinfu
School of Geoscience and Surveying Engineering, China University of Mining & Technology, Beijing, China.
Department of Chemical and Biomolecular Engineering and Polymer Program, Institute of Materials Science, University of Connecticut, Storrs, CT, United States.
Front Chem. 2018 Jul 27;6:310. doi: 10.3389/fchem.2018.00310. eCollection 2018.
Although the development of clay/polymer nanocomposites and their applications have attracted much attention in recent years, a thorough understanding of the structure and the decomposition mechanism of clay/polymer nanocomposites is still lacking. In this research, the intercalation of kaolinite (Kaol) with different alkylamines were investigated by X-ray diffracion (XRD), Fourier-transform infrared spectroscopy (FTIR), and thermogravimetry and differential scanning calorimetry (TG-DSC). The results showed that the intercalation of Kaol/methanol compound with hexylamine (HA), dodecylamine (DA), and octadecylamine (OA) led to the expansion of the interlayer distance and resulted in the dominant basal diffraction at 2.86, 4.08, and 5.66 nm. The alky chains of HA, DA, and OA are tilted toward the Kaol surface in bilayer with an inclination angle of ~40°. The most probable mechanism function, activation energy , and pre-exponential factor were obtained by mutual authentication using KAS and Ozawa methods, itrative and Satava integral method. The average activation energy of the three intercalation compounds are 104.44, 130.80, and 154.59 kJ mol, respectively. It shows a positive correlation with the alkyl chain length. The pre-exponential factor was estimated to be 1.09 × 10, 1.15 × 10, and 4.17 × 10 s, respectively. The optimized mechanism function for the decomposition of alkylamine is α = [(1-α) -1].
尽管近年来粘土/聚合物纳米复合材料的发展及其应用备受关注，但对其结构和分解机理仍缺乏深入了解。本研究通过X射线衍射（XRD）、傅里叶变换红外光谱（FTIR）以及热重分析和差示扫描量热法（TG-DSC）研究了不同烷基胺对高岭土（Kaol）的插层作用。结果表明，高岭土/甲醇复合物与己胺（HA）、十二烷基胺（DA）和十八烷基胺（OA）的插层作用导致层间距扩大，并在2.86、4.08和5.66 nm处出现主要的基面衍射。HA、DA和OA的烷基链在双层中向高岭土表面倾斜，倾斜角度约为40°。通过KAS和Ozawa方法、迭代和Satava积分方法相互验证，得到了最可能的机理函数、活化能和指前因子。三种插层化合物的平均活化能分别为104.44、130.80和154.59 kJ/mol，与烷基链长度呈正相关。指前因子估计分别为1.09×10、1.15×10和4.17×10 s。烷基胺分解的优化机理函数为α = [(1-α) -1]。
