【作者】 倪宇；

【导师】 徐伟箭； 熊远钦；

【作者基本信息】 湖南大学 ， 应用化学， 2007， 硕士

【摘要】 聚硅烷是一类新型σ共轭聚合物,主链全部为硅原子,由于σ电子沿整个硅链广泛离域而显示出特殊优异的光电性能,近年来,它已越来越引起人们的关注,其基础研究、器件制作和应用研究在国际上十分活跃。通过广泛的文献阅读发现,对超声法合成聚硅烷的研究越来越多。与传统的Wurtz法相比,超声法合成的产物分子量更大,分布更加单一,并且由于特殊的工作原理,它还可以在低温下进行反应。在聚硅烷主链的合成方法渐趋成熟后,人们的研究兴趣便转移到含有官能侧基的聚硅烷上来。将官能侧基引到硅—硅主链上能对聚硅烷的物理、化学性质有很大影响。乙烯基基团是一种容易与其自身以及其它有机基团键合的官能团,但是,含取代烯基的单体,在采用常用的Wurtz钠缩合法合成时,都只能得到少量(不足2%)可溶性聚合物,这是由于在Wurtz钠缩合的高温反应条件下发生了交联的原因。但是在较低温度下,交联能够得到一定程度的抑制。超声钠缩合法可以使得聚硅烷的合成温度对比Wurtz钠缩合法能有一定程度的降低,这使含乙烯基官能团的聚硅烷的合成为了一种可能。本课题的工作就是基于上述考虑,研究含乙烯基基团的聚硅烷的合成。在金属钠作用下于惰性溶剂甲苯中,以甲基乙烯基二氯硅烷为原料,使用超声法所合成,还研究了反应温度、时间以及超声功率对合成产物的影响。随后又合成了聚甲基乙烯基二氯硅烷和甲基苯基二氯硅烷的共聚物以及偶联的聚甲基乙烯基硅烷。通过各种方式对合成的产物进行全面的表征,研究了其结构、性质及潜在的应用前景。结果表明,采用超声法成功合成出了聚甲基乙烯基硅烷PMViS,甲基乙烯基二氯硅烷和甲基苯基二氯硅烷的共聚物PMViS-co-PMPS以及偶联的聚甲基乙烯基硅烷,三种产物溶解性良好,分子量较高。通过共聚引入了乙烯基基团的共聚硅烷与聚甲基苯基硅烷相比,紫外特性和热稳定性等方面相差不大,这说明产物能通过共聚来引入乙烯基基团,进而通过乙烯基基团来进行进一步的官能化改性;通过热分析表明,偶联的聚甲基乙烯基硅烷热稳定性良好,这说明普通聚硅烷在引入乙烯基基团之后,通过使乙烯基基团之间出现一定量的偶联能够提高其耐热性能。更多还原

【Abstract】 Polysilanes are a new class ofσ-conjugated polymers with the backbone consisting of tetrahedrally coordinated silicon atoms and different side-chain substituent groups. Due to the extensive delocalization ofσ-electrons along the silicon main chain. Recently, in the world, much attention has been paid on the fundamental research, devices preparing and application of optoelectric polymer materials.Compared with the products from Wurtz-type reaction , the products from the ultrasonic coupling method have higher molecular weighet and more narrow ditribution. Owning to the mechanism of ultrasonic, polysilanes are able to be produced under very low temperture. After the research about the systhesis of polysilane backbone, more and more attention are paid to the research of polysilanes containing fuctional branch. The introduction of fuctional branch into the Si-Si chain has significant influence on the physical and chemical properties. The yied of solvable polysilanes is lower than 2% because of cross-linking resulted from the vinyl group which is easy to cause polymerization. But, it is able to restrain the cross-linking when employing ultrasonic coupling method ,in which relative low temperature is nessary.Therefore, the synthesis of polysilanes containing vinyl group becomes possible. Based on these considerations mentioned above, the synthesis of polysilanes containing vinyl group is investigated in this thesis. Polymethylvinylsilane was synthesized through ultrasonic coupling method using dichloromethylvinylsilane as monomers. The effect of reaction temperature, reaction time and the ultrasonic power on the yield of resulting products was investigated. Then, the poly- -(methlvinylsilane-co-methylphenylsilane) and the cross-linked polymethylvinylsilane were synthesized by the same method and characterized.The results showed that the resulting three products, having high molecualr weight and good solvency, was synthsized by using ultrasonic coupling method. Compared with Polymethylphenylsilane, polysilanes contained vinyl, which was capable of being further functionalized, have similar thermal stability and UV property. The TGA and DSC results showed that the cross-linked polymethylvinylsilane has good thermal stability. Therefore, it is possiable to enhance polysilanes’thermal stability through cross-linking between vinyl groups.更多还原