本研究一開始先合成不同間距基長度的主鏈用液晶單體4,4’-bis(n-hydroxyalkanoxy)azobenzene (n = 6,11) 及側鏈用液晶單體2,2-Bis(hydroxymethyl)propionic-(4-methoxy-azobenzene)alkane (n = 4,6,8,10)，再個別與飽和的二異氰酸酯H12MDI (4,4’-Methylenebis (cyclohexylisocyanate)) 與H6XDI (1.3-Bis(isocyanatomethyl)cyclo hexane) 合成出兩個系列含軟鏈段與不含軟鏈段聚胺基甲酸酯。第一系列的高分子則是將H6XDI與液晶單體以1：1的比例聚合而成。H12MDI 與 PTMO1000以莫耳數2：1的比例形成預聚合物，再導入液晶單體作為鏈延長劑，形成第二系列的液晶PU彈性體。所合成之主，側鏈液晶單體與高分子以FT-IR，NMR鑑定其結構，以DSC，偏光顯微鏡 (POM) 及WAXD分析其熱轉移性質與液晶相態，並以TGA測試高分子之熱烈解溫度。

結果發現，H6XDI系列之液晶聚胺基甲酸酯皆有液晶現象。主鏈型的液晶聚胺基甲酸酯皆為nematic liquid crystalline。側鏈型液晶聚胺基甲酸酯則呈現amorphous的高分子型態。合併型者則大部分傾向於形成nematic liquid crystalline。

至於含柔軟鏈段之H12MDI系列液晶高分子雖然彈性及成膜性很好，卻沒有呈現出液晶現象。有可能是因為H12MDI結構之複雜性導致結晶或液晶不易形成。此外，硬鏈段及軟鏈段之相混合較嚴重也是因素之一。在機械性質方面，合併型的液晶PU彈性體由於主、側鏈都受到液晶分子的增強作用(reinforcement)而呈現較為強韌的性質。

There are two series of azobenzene-based mesogenic diols were prepared, including 4,4’-bis(n-hydroxyalkanoxy)azobenzene/HAZBn (n = 6,11) and 2,2-Bis(hydroxymethyl)propionic-(4-methoxy-azobenzene) alkane/MAPn (n = 4,6,8,10). The first series of nonsegmented main chain, side chain and combined type liquid crystalline polyurethanes were then obtained from the isomolar polyaddition reaction of the above mesogenic diols and 1.3-Bis(isocyanatomethyl)cyclohexane (H6XDI). The preparation of the second series of polymer, the side chain and combined type liquid crystalline polyurethanes elastomers, used the two stage polymerization of H12MDI, PTMO 1000 and both of the mesogenic diols described above. The Fourier transform infrared spectroscopy, nucleus magnetic resonance spectrometer, differential scanning calorimetry, polarizing optical microscope, and wide angle X-ray diffractometer were used for characterizing these polyurethanes.

All the H6XDI based liquid crystalline polyurethanes exhibited enantiotropic nematic liquid crystalline behavior as major., except that the side chain LCPUs acted as amorphous polymers instead of showing liquid crystalline behavior.

As for the H12MDI based liquid crystalline polyurethanes elastomers, they showed good mechanical and elastic properties, especially the combined type, as refer to the biaxial reinforcement effect of the mesogenic group. However, no liquid crystalline behavior was observed under the POM investigation.

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