利用格林納置換鏈成長聚合法合成均一分子量分布之主鏈液晶型聚對位苯及其性質研究

Abstract

本實驗研究是利用格林納 (Grignard) 置換鏈成長聚合法合成出ㄧ系列的聚對位苯高分子 (Poly(p-phenylene) ，PPP) 。透過此法為鏈成長的縮合聚合反應機制，將可得到具均一分子量分布 (monodisperse) 及分子量可藉由改變單體和觸媒比例而使其能預期控制的聚對位苯高分子，進而可更精確的研究及了解其性質。 將一系列不同分子量的聚對位苯高分子進行合成鑑定及基本的性質測試，比較其光學性質、熱性質及微結構現象的趨勢或差異性。包含以膠體滲透層析儀 (Gel Permeation Chromatography, GPC) 測量其分子量與分子量分布情形，透過紫外光-可見光光譜儀 (UV - vis Spectrophotometer) 和螢光光譜儀 (Photoluminescence) 量測其光學性質，利用熱重分析儀 (Thermogravimetric Analyzer, TGA) 與示差掃描熱量計 (Differential Scanning Calorimeter, DSC) 進行熱性質量測。並藉由小角度X光散射 (Small angle X-ray scattering, SAXS) 及廣角度X光散射 (Wide angle X-ray scattering, WAXS) 來觀測聚對位苯高分子的微結構排列情形及晶體結構，並發現此一尚未有文獻確切發表過的新現象，即小分子量PPP有液晶的產生，而高分子量的PPP卻無液晶生成，最後再經由偏光顯微鏡 (Polarized Optical Microscope,POM) 來觀察證實此液晶現象。 總結上述儀器分析結果的數據資訊，獲得以格林納置換鏈成長聚合法所合成出的不同分子量之聚對位苯高分子其基本特性與其微結構方面的認識，致使我們對PPP整體的性質研究探討有其更一步的發展。

In this thesis, a series of monodisperse Poly(p-phenylene) (PPP) were synthesized by Grignard Metathesis chain-growth polymerization. Via this chain-growth polycondensation mechanism reaction, we could yield PPP with narrow polydispersity and that the molecular weight of PPP is controlled by the feed ratio of the monomer to the Ni catalyst. The synthesized PPP were characterized by using various techniques includihg Gel Permeation Chromatography (GPC) to ensure molecular weight and PDI, UV-vis Spectrophotometer and Photoluminescence (PL) to analysis optical characterization, Thermogravimetric Analyzer (TGA) and Differential Scanning Calorimeter (DSC) to analysis thermal property. Furthermore, via Small angle X-ray scattering (SAXS) technique and Wide angle X-ray scattering (WAXS) technique to study the crystalline structure of PPP nanostructure, and then observed the new phenomenon, the low molecular weight PPP could transfer to liquid-crystal, but the high molecular weight PPP couldn’t. In the end, we used Polarized Optical Microscope (POM) techniques to prove it.