【作者】 冯桂双；

【导师】 李长生；

【作者基本信息】 江苏大学 ， 材料学， 2010， 硕士

【摘要】 由于有机/无机复合微球兼具有有机材料和无机材料的优点,并且通过调节两相的组分、尺寸和结构可得到特殊结构和特殊性能的复合微球,近年来受到人们的广泛关注。有机/无机复合微球作为润滑剂具有耐热性好、强度高等特点,并且在制备过程中可以通过调节其制备方法,制备出特殊形态及性能的有机/无机复合微球。本文通过两种不同合成方法制备了具有不同结构和性能的有机/无机复合润滑微球,并对其结构和性能进行了研究,其主要工作如下:(1)插层型复合微球的制备及表征。以苯乙烯(St)、二乙烯基苯(DVB)为有机单体与有机蒙脱土(OMMT)通过悬浮聚合制备有机/无机复合微球。有机蒙脱土是由蒙脱土(MMT)经十六烷基三甲基溴化铵(CTAB)离子交换后得到。有机蒙脱土与有机单体通过超声波混合后,有机单体进入到蒙脱土层间,在引发剂作用下进行自由基聚合反应,反应过程中分子链段在蒙脱土层间进行增长,经8h反应固化,得到了聚苯乙烯/蒙脱土复合微球。利用傅立叶红外光谱仪(FT-IR)、X射线粉末衍射仪(XRD)、透射电子显微镜(TEM)和扫描电子显微镜(SEM)表征了插层型复合微球的微观结构与形貌。结果表明,复合微球内部为插层型结构,即聚合物链段插入蒙脱土层间。用热重(TG)分析法研究了复合微球的热稳定性能,纯聚苯乙烯失重温度为399℃,而MMT、DVB含量分别为5%和10%(质量百分含量,下同)的复合微球失重温度达437℃,提高了38℃。采用ZN-3A泥饼粘附系数测定仪测定了插层型复合微球在钻井液中的润滑性能,结果表明,复合微球能有效的降低钻井液的摩阻系数(K_f),降低了钻井液的滤失量(FL),改进了钻井液的润滑性能。(2)核壳型复合微球、空心微球的制备及表征。以2-甲基丙烯酰氧乙基三甲基氯化铵(MTC)为功能单体与苯乙烯通过分散聚合制备了表面带有正电荷的功能化聚苯乙烯微球。以聚苯乙烯微球为模板,正硅酸四乙酯(TEOS)为前驱体,在碱性条件下水解,前驱体TEOS生成的硅羟基显负电性而被表面带正电荷的聚苯乙烯微球所捕获,从而在聚苯乙烯种球表面形成包覆层,制备了聚苯乙烯/二氧化硅核壳微球,经过煅烧的方法进一步制备了二氧化硅空心微球。通过傅立叶红外光谱仪(FT-IR)、X射线粉末衍射仪(XRD)、透射电子显微镜(TEM)和扫描电子显微镜(SEM)表征了核壳微球及空心微球的微观结构与形貌。以植物油为基础油,采用MR-S10B四球摩擦试验机测试了二氧化硅空心微球的润滑性能。结果表明,在较低载荷下,二氧化硅空心微球具有较好的润滑性能。更多还原

【Abstract】 In recent years, the preparation of organic-inorganic composite microspheres have been widely concerned because such composite microspheres combined the merits of organic materials and inorganic materials and its structure can be obtained by altering the two-phase composition, size and structure. Organic-inorganic composite microspheres as lubricant have some excellent properties, such as great heat-resistant and good strength. In this paper, the composite microspheres with different structures and properties were prepared by two different methods. The structures and properties of those composite microspheres had been studied. The main research contents as follows:（1） Preparation and characterization of intercalated composite microspheres.The intercalated composite microspheres were prepared by suspension polymerization with styrene（St）, divinylbenzene（DVB） and organic montmorillonite（OMMT）. OMMT were prepared by ion-exchange method between sodium montmorillonite（MMT） and cetyltrimethyl ammonium bromide （CTAB） in an aqueous solution. OMMT and organic monomer were mixed by using ultrasonic. And then the organic monomer inserted into the montmorillonite interlayer. When the free radical initiator caused polymerization, the polymer chains were growed up among the layers of OMMT. After 8h of polymerization, the intercalated polystyrene/organicmontmorillonite（PS/OMMT） composite microspheres were obtained.The microstructure and shape of composites were characterized by FT-IR、XRD、TEM and SEM. The result revealed that the polymer chains inserted into the montmorillonite interlayer and formed intercalated composite microspheres. The thermal stability of composites was studied by thermogravimetric analysis （TG）. The TG result showed that the weight loss temperature of pure polystyrene was 399℃. While the weight loss temperature of composite microspheres with 5% MMT and 10% DVB was 437℃, which enhanced 38℃than pure polystyrene microspheres. The lubricity of intercalated composite microspheres in drilling fluid was tested by ZN-3A and. The result showed that the composite microspheres could reduce the friction coefficient, decrease the filter loss and improve the lubricity of drilling fluid.（2） Preparation and characterization of core-shell composite microspheres.The polystyrene microspheres with positively charged were prepared via dispersion polymerization of St with 2-（methacryloyl） ethyl trimethyl ammonium chlorilde （MTC）. Using PS microspheres as template, TEOS as precursor, TEOS hydrolysised under alkaline conditions. The hydrolysate of TEOS with negative charged were captured by the PS template microspheres with positively charged. So the core-shell composite microspheres were obtained by this method. Then the core-shell composite microspheres were treated with high temperature and the hollow SiO₂ microspheres were obtained.The microstructure and shape of core-shell composites microspheres were characterized by FT-IR, XRD, TEM and SEM. The lubricity of hollow SiO₂ was tested by MR-S10B four-ball friction test machine. The result revealed that the hollow SiO₂ microspheres exhibited great lubricity at low load.更多还原