【作者】 谭海林；

【导师】 聂俊；

【作者基本信息】 北京化工大学 ， 高分子化学与物理， 2008， 博士

【摘要】 光聚合制备有机/无机纳米复合材料结合了光聚合与纳米复合材料的优点。为了制备性能优异的有机/无机纳米复合材料,本论文主要从光聚合体系的不同组份着手,利用光聚合制备出有机-无机相通过化学交联的纳米复合材料。本论文的主要工作如下:1、通过Michael加成反应合成了具有甲基丙烯酸酯基团不同链长的单链型季铵盐。利用含可聚合官能团的季铵盐对蒙脱土进行改性,与自由基光聚合体系共混后,通过光聚合制备了有机/无机纳米复合材料。XRD、DMA、电子拉伸研究表明改性的蒙脱土的层间距随链长的增加而增加,所制备的蒙脱土/聚合物复合材料其机械物理性能也随着链长的增加而有所提高。2、通过Michael加成反应合成了具有双-甲基丙烯酸酯基团不同链长的多链型季铵盐。利用含可聚合官能团的季铵盐对蒙脱土进行改性,XRD研究表明改性的蒙脱土的层间距随链长的增加而增加。制备得到的改性有机土与自由基光聚合体系共混后,通过光聚合制备了有机/无机纳米复合材料。XRD研究表明分散在聚合物中的改性蒙脱土的层间距随链长的增加而减小,与单链型季铵盐改性蒙脱土的结果相反。另外DMA、电子拉伸研究表明所制备的蒙脱土/聚合物复合材料其机械物理性能也随着链长的增加有所提高。3、利用TDI将高效的自由基型光引发剂1173阳离子化,然后插层引入蒙脱土层间,制备得到可光引发聚合的活性有机土。制备得到的改性有机土与自由基光聚合体系共混后,通过光聚合制备了有机/无机纳米复合材料。实时红外（RT-FTIR）表明制备的可光引发聚合的活性有机土有较高的引发活性,甚至以1/100（w/w）的活性土在20mW/cm²的光强下转化率也能达到87%。XRD及TEM研究表明改性有机土呈部分剥离和部分插层分散在聚合物基体中。4、利用合成的三乙氧基硅丙基氨甲酰氧基乙基三甲基碘化铵（APS）与缩水甘油丙基三甲氧基硅（GPS）的溶胶-凝胶反应将环氧官能团通过阳离子交换插入蒙脱土层间,通过溶胶-凝胶改性后的蒙脱土在丙酮中具有较好的分散性和稳定性。XRD及TEM研究表明改性有机土与坏氧预聚物混合并进行光聚合后,改性蒙脱土层间与聚合物基体通过化学键交联,具有更好的相容性更利于形成部分剥离和高度剥离蒙脱土/环氧纳米复合材料。另外,利用XRD、TEM和TGA对不同APS/GPS配比形成的复合材料中有机土的分散情况,及不同配比对热稳定性的影响做了研究,结果表明随着缩水甘油丙基三甲氧基硅（GPS）量的增加,改性的蒙脱土在环氧树脂中依次形成有序型剥离和无序型剥离型蒙脱土/环氧纳米复合材料,制备的蒙脱土/环氧纳米复合材料具有较好的热稳定性。5、利用合成的三乙氧基硅丙基氨甲酰氧基乙基三甲基碘化铵（APS）与1173IPS的溶胶-凝胶反应将光引发剂1173活性官能团通过阳离子交换插入蒙脱土层间,制备得到可光引发聚合的活性有机土,有机土具有较大的层间距,可达到2.26-3.65nm。改性有机土与自由基光聚合体系共混后,通过光聚合制备了有机/无机纳米复合材料。实时红外（RT-FTIR）表明随着1173IPS量的增加,改性的有机土具有较快的引发速率和类似的最终转化率,最终转化率可达到90%。XRD和TEM研究表明改性蒙脱土以有序剥离分散在聚氨酯丙烯酸树脂聚合物基体中,制备的蒙脱土/聚合物具有较好的热稳定性。6、通过溶胶-凝胶法,利用四乙氧基硅（TEOS）,1173IPS和甲基丙烯酰氧基丙基三甲氧基硅（MAPS）作为硅源,1173IPS作为光引发剂,MAPS作为改性剂,在光聚合树脂中制备了表面锚接1173光引发剂的活性SiO₂粒子,原位UV光聚合法制备了SiO₂/聚氨酯纳米复合材料。实时红外（RT-FTIR）研究表明,随着1173IPS引发剂浓度的增加,SiO₂/光聚合复合树脂的双键转化率和光固化速率随之增大,最终转化率也增加。相同浓度1173IPS光引发剂,没有经过MAPS改性的双键转化速率较快,具有略高的最终转化率。TEM表明1173IPS和MAPS对形成的SiO₂颗粒的大小和分散情况有重要的影响。较高浓度的1173IPS有利于形成均匀分散SiO₂颗粒,MAPS的改性能进一步提高其均匀分散的特性。此外较高浓度1173IPS能够提高材料的透明性能,MAPS改性对其透明性能有进一步的改善。更多还原

【Abstract】 Preparation of organic/inorganic nanocomposites by UV photopolymerization combines the advantages of both nanocomposites and the UV photopolymerization. To prepare organic/inorganic nanocomposites with excellent properties, different types of organic/inorganic nanocomposites were prepared through different purposes based on the different UV photopolymerization components in the thesis, and the organic/inorganic components were bonded together through chemical bond. The main results was emphasized.1. Ammonium surfactants with methacryloxy group of different chain length were synthesized via Michael-Addition and quatemization reaction. The Na-montmorillonite(Na-MMT) was modified by the ammonium surfactants with polymerizable group through cationic exchange. MMT/polyurethane nanocomposites had been produced by UV initiated polymerization with 5w% organoclay loading. XRD, DMA and the study of tensile properties indicated that the mechanical and physical properties of the nanocomposites increased with the chain length of modifiers.2. Polymerizable ammonium surfactants with two methacrylate alkyl chains were successfully synthesized via Michael-Addition and quaternization reaction. Organoclays containing reactive methacrylate groups were prepared by cationic exchange process. Nanocomposites have been produced by UV initiated polymerization with different organoclay loadings. X-ray diffraction (XRD) spectroscopy showed that the d spacing of organoclay increased with increment of methacrylate alkyl chains length. After organoclay was dispersed in urethane acrylate resin and photopolymerized, the d spacing decreased with increment of the methacrylate alky chains length, which was different to that of the polymerizable ammonium surfactants with methacrylate alkyl single chain. Dynamic mechanical analysis (DMA) showed nanocomposites containing reactive organoclay had high glass transition temperature and storage modulus. Tensile analysis implied that incorporation of reactive organoclay could enhance mechanical and tensile properties of nanocomposites dramatically.3. A photoinitiator 1173TDI was synthesized, which was intercalated into montmorillonite through cationic exchange. The intercalated photoinitiator also had high photoinitiation efficiency, even only 1/100(w/w) modified-clay could initiate the radical polymerization with the 87% acrylate conversion on 20mW/cm~2 exposure. XRD and TEM showed that the MMT was partly intercalated and partly exfoliated in the polymer matrix.4. Reactive epoxy groups were intercalated into the layered silicates through sol-gel reaction of triethoxysilanepropylamineformylethyl trimethyl ammonium iodide (APS) and 3-glycidoxypropyl trimethoxysilane (GPS). The modified organoclay through sol-gel reaction were easy to be dispersed in acetone and formed stable slurry. The slurry was then mixed extensively with epoxy resin to form epoxy-nanoclay composites by photopolymerization. XRD and TEM study showed that the modified clay had good affinity to the epoxy resin, and the resulting epoxy-nanoclay composites exhibited a high degree of clay exfoliation from order exfoliation to highly disorder exfoliation and a good thermal stability property with the increment of GPS.5. Photoinitiator 1173IPS was intercalated into the montmorillonite (MMT) through sol-gel reaction of triethoxysilanepropylamineformylethyl trimethyl ammonium iodide (APS) and 1173IPS. XRD indicated that the d spacing of the modified clay was enlarged to 2.26-3.65nm. The modified clay was then mixed with urethaneacylate oligomer and MMT/polyurethane nanocomposites were prepared by photopolymerization. Real-time FTIR (RTIR) results showed the system had almost the same final conversion but different polymerization rates with different ratios of APS/1173IPS modified clay. XRD and TEM results showed that the modified-clay was exfoliated and dispersed in parallelly alignments as multilayers in the organic matrix.6. UV-curable nanocomposites were prepared by the in-situ photopolymerizaton with nanosilica obtained from sol-gel process of tetraethyl orthosilicate (TEOS), 3-(triethyloxysilyl) propyl methacrylate (MAPS) and 1173IPS. The photoinitiator 2-hydroxy-2-methyl-1-phenylpropane-1-one (1173) was anchored onto the surface of the nanosilica with or without methacryloxypropyltrimethoxysilane (MAPS) modification. The Real-Time Fourier transform IR (RTIR) showed that the double bond conversion and curing rate increased with the increment of 1173IPS, and nanocomposites containning the nanosilica particles without MAPS modification had much higher curing rates than those containning the nanosilica particles with MAPS modification. Transmission electron microscopy (TEM) indicated that MAPS and 1173IPS played an important role on the uniformal dispersion of the nanosilica in the organic matrix. With the increment of 1173IPS photoinitiator, the uniformity was improved, no phase separation took place and with the addition of MAPS, the uniformity was further improved. UV - vis transmittance showed that with the increment of 1173IPS photoinitiator, the transparence was also improved, with the addition of MAPS, the transparence was further improved.更多还原