摘要:
采用十二烷基二甲基卞基氯化铵(DBDA) 和间苯二甲胺(MXDA) 设计并制备了一种新型有机化改性蒙脱土(MMT Ⅱ), 通过球磨法来促进其在环氧树脂中的细化与分散, 制备出具有良好解离结构的MMT Ⅱ/ 环氧纳米复合材料。利用红外光谱(FTIR) 、X-射线衍射(XRD) 和透射电镜( TEM) 表征了新型MMT Ⅱ及其纳米复合材料的结构, 测试了力学性能。结构表征与分析表明, 大颗粒粘土聚集体并不能在搅拌混合过程中分散开, 在固化过程中很难充分解离, 而通过球磨过程中产生的剪切力可促进其分散与细化, 从而获得良好解离结构。MMTⅡ中MXDA 的引入, 减少了季铵盐分子链所产生的悬键, 增加了MMT Ⅱ片层的界面反应性, 大大提高了纳米复合材料的力学性能, 冲击强度由3211kJ / m2 提高到4811 kJ / m2, 提高近50 %, 弯曲强度提高近8 %。
关键词:
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球磨
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解离
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粘土
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纳米复合材料
Abstract:
A novel kind of organic montmorillonite (MMT Ⅱ) , modified with the combination of dodecyl benzyldimethyl ammonium chloride (DBDA) and meta-Xylylenediamine (MXDA) , was prepared by a newly designed modification method , and finely exfoliated MMT Ⅱ/ epoxy nanocomposites were achieved by the aid of shearing force of ballmilling. Fourier transform infrared spectroscopy (FTIR) , X-ray diffraction (XRD) and transmission electron microscopy( TEM) were used to characterize the structure of MMTⅡ and the corresponding nanocomposites. The mechanical properties were tested. The results show that large agglomerates of MMT Ⅱ can not be homogeneously dispersed by generalstirring , which only induces an intercalated or partially exfoliated structure of MMT Ⅱin epoxy matrix at most . Whereasthe exfoliation of the retained intercalation structure or agglomerates can be promoted by external shearing force of ballmilling, which induces homogeneously dispersed nano-sheets of MMT Ⅱ and enhances mechanical properties. Impactstrength can be increased up from 3211 kJ / m2 to 4811 kJ / m2 , which is about 50 % higher than that of pristine matrix ,and the flexural strength can also be enhanced by about 8 % higher.
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