含雙苯基乙烷液晶基之鐵電性側鏈液晶聚甲基丙烯酸酯之合成研究

Abstract

本研究主要是合成兩系列有雙苯基乙烷團基之旋光性層列液晶聚甲基丙烯 酸酯，兩者皆是以聚甲基丙烯酸酯為高分子主鏈，並含有8，9， 10，11 個次甲基單位之柔軟間聚，所合成之液晶單體及聚合物皆以微熱差掃描卡 計和偏光顯微鏡測定其液晶轉移溫度及鑑定其液晶相。研究結果顯示，第 一系列是含有一苯基與雙苯基乙烷團基之液晶單體及聚合物，在偏光顯微 鏡下很容易形成垂直配向排列，除了層列A液晶相外，無法觀察到是否有 旋光性層列C液晶相；所合成之四種液晶聚合物，熱分析結果顯示，有兩 個液晶轉移溫度，其中一個液晶相為層列A相，另一個液晶相在偏光顯微 鏡下無法辨識其為何種層列相。第二系列係含有一氯苯基和雙苯基乙烷團 基之液晶單體和聚合物，單體在偏光顯微鏡下呈現膽固醇型液晶相，也很 容易形成垂直配向排列；所合成之四種液晶聚合物，熱分析結果顯示有一 個液晶轉移溫度，其皆呈現層列A液晶相，其中含較長間距(分別為10和11 個次甲基)之聚合物則呈現旋光層列C液晶相。 In this study, two series of chiral smectic liquid crystall- ine polymethacrylates containing diphenylethane groups in their mesogenic side groups. The synthesized polymers contain contain the same polymethacrylate backbone and 8 to 11 methylene units as spacers. The obtained polymers and monomers are char- acterized by differential scanning calorimetry and optical polarizing microscopy. The first series of monomers containing, one belongs to smectic A phase and the other smectic phase does not show characteristic texture under optical polarizing microscope. The second series of monomers containing a chloro -phenyl and a diphenylethane groups in their mesogens, display a cholesteric phase. They also tend to form the homeotropic texture phase. They also tend to form the homeotropic texture under optical polarizing microscope.The corresponding polymethacryl- ates exhibit a smectic A phase. Both polymethacrylates containing respectively 10 and 11 methylene units in their spacers are the only two polymers show a chiral smectic C texture under optical polarizing microscopic observation.