Structure and Properties of Poly(n-pentyl-n-alkylsilanes). 2
Structure and Properties of Poly(n-pentyl-n-alkylsilanes). 2
复制标题
聚（正戊基-正烷基硅烷）的结构和性能。
DOI：
10.1021/ma946425l
复制
发表时间：
1993
期刊：
影响因子：
5.5
通讯作者：
J. Koutsky
中科院分区：
文献类型：
--
作者：
Bruce M. Klemann;R. West;J. Koutsky
用紫外吸收光谱、差示扫描量热法和X射线衍射法研究了聚正戊基正己基硅烷（C5-C6）、聚正戊基正辛基硅烷（C5-C8）和聚正戊基正十二烷基硅烷（C5-C12）的固态电子性质和结构。在低温下，C5-C6是具有全反式骨架构象的半结晶。在加热时，它转变为在许多聚硅烷中观察到的六方、柱状、condis结晶相。C5-C8在高于和低于其一级转变温度-32 °C时均表现出六方柱状中间相。发现这种类型的行为是具有两个或三个碳原子的侧链不对称性的聚（n-烷基-n-烷基硅烷）的特征。这些不结晶聚合物的一级跃迁的存在和在冷却时观察到的UV热致变色红移最有可能是σ键合的硅主链和烷基侧链之间的极化相互作用的结果，这与Schweizer共轭聚合物模型的预测一致。
The solid-state electronic properties and structures of poly(n-pentyl-n-hexylsilane) (C5-C6), poly(n-pentyl-n-octylsilane) (C5-C8), and poly(n-pentyl-n-dodecylsilane) (C5-C12) have been investigated using UV absorption, DSC and X-ray diffraction. At low temperatures, C5-C6 is semicrystalline with an all-trans backbone conformation. Upon heating, it transforms to the hexagonal, columnar, condis crystalline phase observed in many polysilanes. C5-C8 exhibits the hexagonal, columnar mesophase both above and below its first-order transition temperature of -32 °C. This type of behavior is found to be characteristic of poly(n-alkyl-n-alkyl'silanes) with a side-chain asymmetry of two or three carbon atoms. The existence of first-order transitions and the observation of UV thermochromic red shifts upon cooling for these polymers which do not crystallize are most likely the result of polarization interactions between the σ-bonded silicon backbone and the alkyl side chains, which is consistent with the predictions of the model of Schweizer for conjugated polymers.