• 作者： Chen, Yun; Hsieh, Chen-Yang
• 中文摘要： 藉由NCA方法並利用三乙基胺或啶為起始劑,二氯甲烷或二氧陸環為溶劑,合成黏度平均分子量在11,000-43,400之光學活性高分子-聚(L-麩胺酸甲酯)(PMLG)。分子量43,400之聚(L-麩胺酸甲酯)再與苯甲醇,正十二醇及 1-苯基乙醇進行酯交換反應製備聚(L-麩胺酸烷基酯)類PBLG、PBDoLG、PDoLG以及PPeLG。這四種高分子以及PMLG(啶起始者)均經由IR以及圓偏光二色光譜(CD)證實具有.alpha.-helix的高級構形,並以偏光顯微鏡觀察其液晶紋理。其中PBLG和PBDoLG的間-苯酚濃溶液顯現膽石醇型的液晶形態,由偏光顯微鏡照片上黑白相間條紋,推算得PBLG及PBDoLG之膽石醇型螺距(cholesteric pitch)分別為 20-32.mu.m(20.1-27.6wt%)及40.mu.m(30.8wt%)。
• 英文摘要： Poly(.gamma.-methyl L-glutamate) (PMLG), having viscosity molecular weight (M/sub v/) between 11,000 and 43,400, were prepared by ring-opening polymerization of.gamma.-methyl N-carboxy L-glutamate anhydride (NCA) under four different conditions. Poly(.gamma.-benzyl L-glutamate)(PBLG), poly(.gamma.-benzyl L-glutamate-co-.gamma.-dodecyl L-glutamate) (PBDoLG), poly(.gamma.-dodecyl L-glutamate)( PDoLG), and poly(.gamma.-1-phenylethy L-glutamate) (PPeLG) were prepared by the ester exchange reaction of PMLG(M/sub v/=43,400) with corresponding alcohols. The higher order conformations of these poly(L-glutamates) were investigated by infrared spectra (IR), circular dichroic spectra (CD), and polarized microscope. The conformation of PMLG depends heavily on polymerization conditions, and can exist in .alpha.-helix, .beta.-sheet, or both. PBLG and PBDoLG exist mainly in .alpha.-helical conformation in 1,2-dichloroethane solution and film state, while for PDoLG and PPeLG both .alpha.-helix and .beta.-sheet coexist. The PBLG and PBDoLG form cholesteric liquid crystalline phases in m-cresol, and their cholesteric pitches are 20-32.mu.m(20.1-27.6wt%) and 40.mu.m (30.8wt%), respectively.
• 中文關鍵字： 聚(L-麩胺酸脂); .gamma.-甲基N-羧基L-麩胺酸脂酐; 構形; 液晶; 圓偏光二色光譜
• 英文關鍵字： Poly(L-Glutamates); .Gamma.-Methyl N-Carboxy L-Glutamate Anhydride; Conformation; Liquid Crystal; Circular Dichroic Spectrum