臺灣博碩士論文加值系統

　　本研究是以（Ｓ）-乙基-乳酸酯為原料，合成一系列含不對稱碳為中心之新光學活性（Ｓ）-1-烷氧基-2-丙醇材料，再製備兩系列之三苯環鐵電性液晶化合物，分別為
　　系列Ｉ：4-〔（S）-1-烷氧基-2-丙氧羰基〕苯-4'-辛氧基雙苯-4-碳酸酯（nAPCPOBPC；n = 2-6）
　　系列Ⅱ：4-〔（Ｒ）-1-烷氧基-2-丙氧羰基〕雙苯-4'-辛氧基苯-4-碳酸酯（nAPCBPOPC；ｎ= 3-6）
　　使用微差熱掃描卡計（DSC）及偏光顯微鏡（POM）來鑑定系列Ｉ與系列Ⅱ之液晶相，及探討（Ｓ）-1-烷氧基-2-丙醇中烷氧基鏈長與液晶性的影響，並用自動極化裝置（Automated Polarization Tested；APT）測其自發極化率值（Ps）。
　　系列Ｉ，nAPCPOBPC；n =3，4有SmA及SmC*相產生，而n =5只有SmA相，但是 n = 2，6 時則顯現無液晶性質。
　　系列Ⅱ，nAPCBPOPC；只有 n =4 有SmC*相產生。
　　比較系列Ｉ、Ⅱ，系列Ｉ中SmC*相範圍高達50 C，而系列Ⅱ中SmC*相範圍卻只有8 C。
　　自發極化值（Ps）測定結果，系列Ｉ，nAPCPOBPC；n =3 時Ps為4.8nc/cm2，n =4 時為20.3nc/cm2。系列Ⅱ，nAPCBPOPC；n =4時Ps值只有0.4nc/cm2。
　　聚碳矽鐵電性液晶聚全物，是以1-甲基-1-環矽丁烷為單體，利用正丁基鋰為促進劑在0 C進行陰離子開環聚合反應，再與液晶基單體4-〔(R)-1-丁氧基-2-丙氧基〕苯-4'-（十一烷-10-乙烯氧基）雙苯-4-碳酸酯進行接枝反應，得到不含雙鍵之〔4-〔(R)-1-丁氧基-2-丙氧基〕苯-4'（十一烷-10-乙烯氧基）雙苯-4-碳酸酯〕矽丁烷為主鏈之鐵電性液晶聚合物。分子量為Mn =32000，Mw/Mn =1.35。
　　單體MO11-2-1液晶相範圍（第一次冷卻）：Ｋ 11.09 SmC* 66.38 SmA 128.64 Ｉ；聚合物 PO11-2-1 液晶相範圍（第一次冷卻）：Tg 34.28 SmC* 135.23Ｉ。
　　所有合成出來的化合物 nAPCPOBPC、nAPCBPOPC、液晶單體MO11-2-1和聚合物PO11-2-1都以IR、1H-NMR、13C-NMR及Mass等光譜或圖譜確定其化學結構。

　　A series of new optically active compounds, (S) -1-alkoxy-2-propanols, has been designed and synthesized from ethy1 (S)-lactate as chiral building blocks for the preparation of chiral materials. Thus, two series of the derivatives, 4-[(S)-1-alkoxy-2-propoxycarbonyl] pheny1-4'-octoxybipheny1-4-carboxylate (nAPCPOBPC;n = 2-6) of the series I and 4-[(S)-1-alkoxy-2-propoxycarbony1] bipheny1-4'-octoxypheny1-4-carboxylate (nAPCBPOPC; n = 3-6) of the series Ⅱhave been prepared for the investigation of liquid crystalline properties as a function of the alkyloxy chain length near to the asymmetric carbon.
　　The transition temperatures of the mesophases for series Ⅰand Ⅱ were determined by DSC in conjunction with optical microscopy. The mesophase identification was carried out principally by polarized optically microscopy.
　　For the series Ⅰ, nAPCPOBPC with n = 3 and 4 showed the banded focal-conic fan texture of the chiral smectic C phase and smectic A phase, whereas nAPCPOBPC with n = 5 exhibited only smectic A phase and nAPCPOBPC with n = 2 and 6 showed no liquid crytalline properties. On the other hand, nAPCBPOPC of the series Ⅱshowed no chiral smectic C phase for each member except for the n = 4 derivative. nAPCPOBPC (n=3 and n=4) show the temperature range of the chiral smectic C phase around 50 C, whereas nAPCBPOPC (n=4) of the series Ⅱshowed only 8℃. The value of Ps were determined by Automated Polarization Tested in an a.c. field of the frequency 100 Hz. For nAPCPOBPC (n=3) a value of 4.8 nc/cm2 was obtained.For the compound nAPCPOBPC(n=4) values up to 20.3 nc/cm2 and for the compound nAPCBPOPC (n=4) down to 0.4 nc/cm2 are observed.
　　Ferroelectric side-chain liquid crystalline polymer, PO11-2-1 with Mn = 32000 and Mw/Mn =1.35 was prepared by platinum catalyzed hydrosilation graft reactions between poly(1-methy1-1-silabutane) and 4-[(R)-1-butoxy-2-propoxy]pheny1-4'-(undec-10-enyloxy)bipheny1-4-carboxylate, MO11-2-1. The phase sequence and transition temperature of the monomer as determined using DSC and POM were gived below:
　　The phase sequence and transition temperature of the monomer and polymer as determined using DSC (1st cooling) POM were given below:MO11-2-1, K 11.09 SmC* 66.38 SmA 128.64 I; PO11-2-1, Tg 25 SmC* 135.23 I.
　　Structure of the nAPCPOBPC, nAPCBPOPC, monomer, MO11-2-1 and polymer, PO11-2-1 were determined by 1HNMR, 13CNMR and Mass spectroscopic investigations.