特种橡胶/有机蒙脱土纳米复合材料的结构与性能研究

【作者】 高（钅监）明；

【导师】 宋国君； 彭智；

【作者基本信息】 青岛大学 ， 材料学， 2008， 博士

【摘要】 本课题采用实验室自制的有机蒙脱土,通过机械混炼插层法制备了多种特种橡胶/有机蒙脱土纳米复合材料。采用透射电子显微镜(TEM)和X射线衍射仪(XRD)研究了纳米复合材料的结构,研究了蒙脱土含量对纳米复合材料的力学性能、热稳定性能、耐油性能等的影响。采用动态热机械分析仪(DMTA)研究了复合材料的动态力学性能。透射电子显微镜(TEM)和X射线衍射仪结果显示:氟橡胶/有机蒙脱土纳米复合材料为插层型纳米复合材料,氢化丁腈橡胶/有机蒙脱土纳米复合材料为剥离型纳米复合材料,氯磺化聚乙烯/有机蒙脱土纳米复合材料为剥离型和插层型共存的纳米复合材料,蒙脱土片层均匀的分布在橡胶基体中,统计表明片层的平均厚度约为10nm,最大的聚集体的片层厚度达到40nm,推断有一小部分片层剥离成单晶层的形式,厚度为1nm。力学性能结果显示,有机蒙脱土具有极高的长径比以及其在橡胶中的精细分散结构使得特种橡胶/有机蒙脱土纳米复合材料具有优异的力学性能。橡胶/蒙脱土纳米复合材料的硬度、拉伸强度和拉断仲长率远高于碳黑填充体系。在蒙脱土含量较低时,复合材料的力学性能随蒙脱土含量的增加而增大。研究了特种橡胶/有机蒙脱土纳米复合材料的热稳定性、耐油性能和老化性能。结果显示,由于蒙脱土片层具有优异的气体阻隔性能,该类橡胶/蒙脱土纳米复合材料具有优异的热稳定性和耐油性能。老化后由于复合材料的交联网络更加均匀,纳米复合材料的拉伸强度、定伸应力均有较大的提高。蒙脱土在小用量下可以提高特种橡胶/有机蒙脱土纳米复合材料的耐磨耗性能,用量增加到一定值时,由于蒙脱土聚集体的形成而导致应力集中,对复合材料的磨耗性能产生负面影响。采用动态热机械分析仪(DMTA)研究橡胶/蒙脱土纳米复合材料的动态力学性能,结果显示:与其它填料相比,具有较高长径比的蒙脱土对橡胶大分子链有更强的限制作用,因此橡胶/蒙脱土纳米复合材料具有优异的动态力学性能,纳米复合材料在保持原有抗湿滑性能的同时具有更小的滚动阻力。油封干磨试验结果显示,蒙脱土的加入使得氟橡胶、氢化丁腈橡胶油封的干磨性能提高,因此提高橡胶油封的使用寿命。并对橡胶/蒙脱土纳米复合材料的补强机理、耐溶剂性能以及耐干磨机理进行了探讨。更多还原

【Abstract】 In this research, several special purpose rubber/OMMT nanocomposites have been prepared by direct mixing intercalation method. Organic montmorillonite were prepared in our lab. The structure of nanocomposite was studied by TEM and XRD. The effects of OMMT content on mechanical properties, oil resistance, thermal stability of rubber/OMMT nanocomposites were studied. The dynamic mechanical properties of nanocomposites were studied by DMTA.The results of TEM and XRD showed that the OMMT layers were intercalated into the FKM matrix, the OMMT layers were exfoliated in the HNBR matrix and the OMMT layers were half-exfoliated in the CSM matrix. The OMMT layers were dispersed well in the rubber matrix. According to statistical data, average thickness of layers was 10nm, and the thickness of the biggest layers was less than 40nm, only a few layers were exfoliated in monolayer whose thickness was about 1nm.The results of mechanical properties showed that the OMMT layers with high aspect ratio and fine dispersed structure endowed the nanocomposites with excellent mechanical properties. The hardness, tensile strength and elongation at break of rubber/OMMT nanocomposites were much higher than those of rubber filled with carbon black. The results showed that the mechanical properties of nanocomposites improved with the increased of OMMT content when the OMMT content is lower.The thermal stability, oil resistance and aging properties of special purpose rubber/OMMT nanocomposites were investigated. The nanocomposites had excellent thermal stability and swell property because of the excellent gas barrier property of OMMT layer. The tensile strength and stress at certain elongation increased after aging due to the improved uniformity and densification of cross-linking network.When the OMMT content is small, the abrasion properties of special purpose rubber/OMMT nanocomposites can be improved. When the OMMT content increased to a certain value, the re-aggregation of OMMT has a negative effect on the nanocomposites.The dynamic mechanical properties of nanocomposites were studied by DMTA. The results showed that the nanocomposites had excellent dynamic mechanical property and a good rolling resistance because the OMMT layers had much more restriction to the rubber chains.更多还原