Polysiloxanes with Periodically Distributed Isomeric Double-Decker Silsesquioxane in the Main Chain
Polysiloxanes with Periodically Distributed Isomeric Double-Decker Silsesquioxane in the Main Chain
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DOI：
10.1021/ma900124x
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发表时间：
2009-05-12
期刊：
影响因子：
5.5
通讯作者：
Kawakami, Yusuke
中科院分区：
文献类型：
--
作者：
Hoque, Md. Asadul;Kakihana, Yuriko;Kawakami, Yusuke
合成了[（2-甲基丙基）羟基硅基]桥联的双层倍半硅氧烷，采用分步沉淀法和硅胶柱色谱法得到了其立体异构体，其结构经H-1、Si-20 NMR和单晶X-RD确证。在三（五氟苯基）硼烷催化下，纯顺式、反式和混合异构体与硅烷封端的八甲基四硅氧烷通过交叉脱氢偶联缩聚反应，得到了完全交替结构的双层德克尔倍半硅氧烷及其八甲基四硅氧烷。所有的聚合物显示出显着增加的玻璃化转变温度，与线性聚（二甲基硅氧烷）相比。透明的有机可溶性聚合物通过简单的流延方法得到自支撑膜。
[(2-Methylpropyl)hydroxysilyl]-bridged double-decker silsesquioxane was synthesized, and its stereoisomers were obtained by fractional precipitation followed by silica gel column chromatography, and their structures were confirmed by H-1 and Si-20 NMR and single crystal X-RD. The pure cis, trans and mix isomer polymerized with silane-terminated octamethyltetrasiloxane via cross-dehydrocoupling polycondensation catalyzed by tris(pentafluorophenyl)borane to give completely alternating structure of the double decker silsesquioxane, and their octamethyltetrasiloxane. All the polymers showed significantly increased glass transition temperature, compared with linear poly(dimethylsiloxane). Excellently transparent organo-soluble polymers gave self-supporting film by simple casting method.