含□吩側鏈液晶聚矽氧烷之合成

Abstract

本研究的主要目的是要合成含□吩側鏈液晶高分子，探討□吩環對所合成化合物液晶行為的影響。本研究選擇以聚矽氧烷為高分子主鏈。以3至11個亞甲基為柔軟間距，液晶基係以□吩環接上兩個苯環為主要結構，以(s)-2-methyl-1-butanol 及 (s)-2-chloro-4-methyl valeric acid 為末端基，所合成的單體經矽氫氧化反應接到聚矽氧烷主鏈上。合成所得單體以核磁共振光譜儀、紅外光譜儀鑑定其結構。所有單體及聚合物皆以微差掃描卡計、偏光顯微鏡、X-ray鑑定液晶相轉移溫度及鑑定其液晶相。研究的結果顯示第一系列的單體除IM外，均具有液晶相，而聚合物均具有液晶相。第二系列單體及聚合物均具有液晶相。所合成的液晶聚合物具有開發作為管柱層析儀之靜相填充物的潛力。所合成的液晶聚合物具有開發作為管柱層析儀之靜相填充物的潛力。

The goal of this research is mainly focused on the synthesis of side chain liquid crystalline polymers containing thiophene-based mesogens. Two series of new side-chain liquid crystalline polymers are prepared according to careful molecular design of polymer backbond , spacer, mesogen and end group. Polysiloxane is used as the polymer backbond . Three to eleven methylene units are used as flexible spacer Phenyl-ethynyl-thiophene group is designed for the mesogen , and a (s)-2-methyl -1-butanol and a (s)-2-chloro-4-methylvaleric acid are designed for the end groups . The prepared liquid crystal monomers are grafted onto the polysiloxane backbond via hydrosilation reaction . The obtained monomers and polymers are characterized by IR , NMR and their mesomorphic properties are determined by DSC , optical polarizing microscope and X-ray . Most of the first series of monomers and polymers present mesomorphic properties . Monomer IM is the only one that present no mesophase . All of the second series of monomers and polymers Which contain three aromatic rings present mesomophic properties . The synthesized liquid crystalline polymers have potential applications in the field of stationary phase of column chromatography .