【作者】 王晓晨；

【导师】 冯圣玉；

【作者基本信息】 山东大学 ， 高分子化学与物理， 2010， 硕士

【摘要】 氨(胺)基官能化聚硅氧烷除具有聚硅氧烷许多优良性能外,还可利用其含氮官能基的反应活性,与其他聚合物反应后形成具有特殊性能的聚合物,保留了有机聚硅氧烷优异性能又赋予其新的性能,该类聚合物在许多领域得到广泛应用。一些氨(胺)基的引入却降低了聚硅氧烷的热稳定性,影响了在诸多方面的使用。研究并分析该类聚合物的热降解规律及其影响因素,对于控制热降解反应、更好地利用该类化合物以及改进和研制具有更优异性能的聚合物具有十分重要的意义。同时,在聚硅氧烷主链上引入氨(胺)基官能团进行化学改性引起了人们极大的兴趣。由于稀土元素具有独特的电子层结构,在受到紫外光激发的时候表现出优良的光学性能。因而,通过化学键将稀土离子配合物接枝到有机聚硅氧烷基质上,可以制备兼具优异发光性能和稳定的物理化学性能的复合材料,在很大程度上拓宽了聚硅氧烷的应用领域。以N-2-氨乙基-3-氨丙基甲基二甲氧基硅烷(AEP)、八甲基环四硅氧烷(D4)、六甲基二硅氧烷(MM)为起始反应物,采用开环聚合法合成了一系列氨基官能化聚硅氧烷(AEP-PS),采用红外分析(IR)、热重分析(TGA)和裂解气质联用(PY-GC-MS)等方法研究了氨基官能化聚硅氧烷在氮气和空气气氛下的热降解行为,分析了裂解产物。热降解行为和热稳定性的研究结果表明,侧链氨基官能团的引入影响了聚硅氧烷的稳定性,降解反应分为分子链间作用和分子链内作用两种,以链内回咬反应为主。氨基官能化聚硅氧烷的热降解过程分为100℃-350℃和400℃-800℃两个阶段,降解产物多是小分子环体。由于产物降解时的环境影响到降解产物的种类,因此探讨了不同气氛下的热降解机理。通过酰胺化反应将氨基聚硅氧烷修饰成相应的酰胺基聚硅氧烷基质,制备发光性能良好的含稀土铕(发红光)、铽(发绿光)、钐(发红光)和镝(发绿光)的聚硅氧烷(侧链酰胺基官能化聚硅氧烷、端酰胺基官能化聚硅氧烷、酰胺基官能化硅树脂)-稀土复合发光材料,测试和分析了复合发光材料的各种性能。酰胺基聚硅氧烷基质中不同的共轭基团导致复合材料的发光性能的差异。材料内部稀土离子与有机基团发生配位作用,受到光激发时,它们之间发生有效的能量传递过程。更多还原

【Abstract】 Amidofunctionalized polysiloxanes, possessing a variety of unique and superior properties, play important roles in modifitions of organic polymers, such as the copolymerization of polysiloxanes and organic polymers, with the aid of the reaction activity of the aminofunctional groups, to endow the organic polymers with the excellent properties of the polysiloxanes. With the rapid development of these kinds of polymer in silicone chemistry, amido functionalized polysiloxanes have been widely applied in many research fields. However, their applications are limited to some extent due to the decomposition or rearrangement under certain conditions. So understanding their rearrangement conditions and mechanisms will be of great important values for the control, improvement and application of these compounds. At the same time, the introductions of amido (acylamido) groups in main chains of polysiloxanes have aroused great interest. To our best knowledge, lanthanide ions can exhibit their excellent photophysical abilities under UV light excitation because of their unique electron configurations. Therefore, the properties of the materials can be improved by covalently grafting the lanthanide complexes to the polysiloxane backbone. The organic ligands can reinforce the energy absorption efficiency and the inorganic portions of the structure offer good mechanical properties. Thus, some stable composite materials with excellent luminescent propertities were prepared in the modification process, by grafting the lanthanide complexes to organopolysiloxanes via chemical bonds. To some extent, the applications of polysiloxanes were developed.A series of amino functionalized polysiloxanes have been synthesized and characterized in ring-opening polymerization with materials of coupling agent (AEP), octamethylcycoltetrasiloxane (D4) and hexamethyldisiloxane (MM). Thermal degradation behaviors have been investigated by Infrared Spectrometry (IR), Thermogravimetric analysis (TGA) and Pyrolysis-Gas Chromatography-Mass Spectrometry (PY-GC-MS) in N2 and air atmosphere. The results show that amido groups in side chain influence the thermal stability. The decomposition processes, which took place in both intramolecular chains and intermolecular chains, are mainly biting-back reactions. And the process is divided into two stages ranging from 100℃to 350℃and 400℃to 800℃with the formation of oligomers. Since the atmospheres impact on the structures of thermal degradation products, two thermal degradation mechanisms of aminopolysiloxanes are proposed.Amidopolysiloxanes matrixes were modified by acylamidation reactions to prepare some luminescent polysiloxanes (side chain acylamidopolysiloxane, terminated acylamidopolysiloxane and acylamidoresin)-rare earth composite materials. Narrow-width green emissions are achieved for Tb3+ and Dy3+ composite materials. Narrow-width red emissions are achieved for Eu3+ and Sm3+ composite materials. In conclusion, the different conjugate groups of modified polysiloxanes led to diverse luminescent properties of complexed materials. The excellent emissions mean that the efficient coordination effect and intramoleenlar energy transfer process between polysiloxane groups and lanthanide ions took place within these molecular-based complexed materials.更多还原