【作者】 林涛；

【导师】 牟其伍；

【作者基本信息】 重庆大学 ， 材料物理与化学， 2009， 硕士

【摘要】 本论文先对钙基膨润土进行钠化处理,对钠化改性剂的选择以及钠化剂用量、钠化反应温度、钠化反应时间等因素对膨润土特性的影响进行了研究。再以十八烷基三甲基溴化铵(OTAB)作插层剂,采用阳离子交换法对钠基膨润土进行有机改性。用单因素实验轮换法考察固液比、配料比、时间、温度及PH值等实验条件对改性效果的影响,同时借助XRD衍射、热失重及红外光谱对有机土的结构和性能进行了表征。最后以双酚A型环氧树脂和制备的有机钠基膨润土为原料,利用插层聚合法制备环氧树脂/膨润土复合材料,研究不同处理方法和工艺参数对材料性能的影响。利用XRD和SEM对环氧树脂/膨润土复合材料的插层情况以及结构进行表征,利用万能力学实验机、冲击实验机、TGA、西林电桥等研究了材料的机械、热学以及电学等方面的性能。实验结果表明:以碳酸钠为钠化剂,按照优化工艺所制备的钠基膨润土物化性能优于原土;XRD测试表明用有机插层剂对钠基膨润土进行插层可以明显增大其层间距,得到实验最佳工艺条件为:配料比为110mmol/100g,固液比为2/100,反应时间为1h,反应温度为80℃,体系PH值为10。按照最佳工艺所制备的有机膨润土的层间距由1.081nm增加到了2.025nm,FTIR和TGA测试显示有机膨润土保持了硅酸盐基本骨架,同时含亚甲基基团的有机物已经进入到层间结构中,增强了疏水性;有机膨润土与环氧树脂在中温下进行搅拌混合有利于膨润土在复合材料中的分散并提高复合材料性能。运用单因素实验循环法对复合材料的固化工艺进行了优化,最佳固化工艺参数为:固化时间3.5h、固化温度100℃、脱泡时间20min;XRD测试表明,环氧树脂的进一步插层使膨润土层间距增大,部分膨润土已达到剥离的程度;在有机膨润土含量为2%~4%时,复合材料的拉伸强度和冲击强度有最佳值;材料断面的SEM图显示,环氧树脂断面光滑平整,为脆性断裂,而复合材料断面有较多银纹和微裂纹,表现为韧性断裂;TGA实验表明,复合材料的初始热分解温度比环氧树脂提高了18.6℃;复合材料的介电强度和介电常数在有机膨润土含量为2%～4%时有最佳值。更多还原

【Abstract】 Firstly, this paper has sodium modified the Ca-bentonite to prepared the Na-bentonite, then studied the selection of sodium compounds and the effect of the content of sodium compounds、the temperature of sodium modification、the time of sodium modification on the property of bentonite. Na-bentonite was organic modified by cation exchange on clay surface by using Octadecyl Trimethyl Ammonium Bromide (OTAB) as intercalation agent. Single factor experiment with the rotation of inspected the ratio of solid to liquid, the ingredients, time, temperature and pH value on the impact of organic soil conditions. and Analysis the structure and performance of organic soil using XRD, TG and FTIR. At the end, the experiment prepared the epoxy/bentonite composites in the method of intercalation polymerization, and studied the effect of different processing method and processing parameters on the materials’property, and used the XRD and SEM to test epoxy/bentonite composites’modification and structure, used the omnipotent mechanical equipment、impact equiment、TGA、Schering bridge and so on to test composites’mechanical、thermal and electric properties. The result indicates: the property of Na-bentonite which is sodium modified by NaCO3 and followed the optimal process is better than Ca-bentonite; XRD testing indicated that the lamellar distance of Na-bentonite can be obviously extended by the octadecylamine, the optimum conditions:the ratio of solid to liquid 2/100, the ingredients 110mmol/100g, time 1h, temperature 80℃and pH value 10. The lamellar distance modified by the optimal process improved from 1.081nm to 2.025nm. FTIR and TGA testing indicated that the fundamental structure of the organobentonite didn’t vary, meanwhile the octadecylamine has been inserted into the lamellar to improve the hydrophilic property;the experiment claims that to choose the method which is to mix the organicbentonite with the epoxy resin firstly at a high temperature is better for the organicbentonite to scatter in the composites and to improve the materials’synthetical property. The experiment used Single factor experiment determining the optimum conditions:time3.5h、the curing temperature 100℃、time of deaeration 20min; XRD testing indicates that the modification of epoxy resin extends the lamellar distance, some of the bentonite has been stripped; on the 2%~4% content of bentonites, the composites’tensile strength and impact strength has reached the best situation; the SEM of materials’fracture surface indicates that the epoxy resin’s fracture surface is typically fragile fracture, the composites’fracture surface has initiated a lot of extremely tiny flaw, that’s tenacious characteristic; TGA experiment indicates the initial resolution temperature is 18.6 higher than epoxy resin; the composites’breakdown electrical field and the dielectric constant have a best situation when the content of the bentonite is 2%~4%.更多还原