Synthesis Of Liquid Crystalline Networks Containing Fluoronatied Units And Isosorbide Groups

Due to the advantages of fluorinated liquid crystals, such as low viscosity, high resistivity, good stability, suitable dielectric constant, rapid response and so on, fluorinated liquid crystalline materials become very important in the display field. According to the difference of liquid crystalline system in which they are, the changes of position and number in molecules, fluorine atoms make fluorinated liquid crystals possess diverse properties. At the same time, side-chain and terminal fluorinated compounds can raise the solubility of other liquid crystals in mix LCs due to fluorine’s greasy solubility. The fluorinated liquid crystals own high resistivity, low viscosity, rapid response, due to the introduction of the atom of fluoride.In this dissertation,eight liquid crystalline monomers were synthesized. which include4-cyano-3-fluorophenyl-4-(undec-10-enoyloxy)benzoate(M1),4’-(4-(allyloxy)benzoyloxy)ph-enyl4-cyano-3-fluorophenyladipate(M2),6-(2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-pentadecafluoroocta-noyloxy)hexahydrofuro[3,2-b]furan-3-y14’-(4-(undec-10-enoyloxy)benzoyloxy)biphenyl-4-yl adipate(M3),1-(4’-(4-(allyloxy)benzoyloxy)biphenyl-4-yl)10-(6-(2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-pentadecafluorooctanoyloxy)hexahydrofuro[3,2-b]furan-3-yl)decanedioate(M4),4-(4-(allylox-y)benzoyloxy)biphenyl-4-yl-4-cyano-3-fluorophenyl adipate(M5),4-(4-(undec-10-enoyloxy) benzoyloxy)phenyl4’-(allyloxy)biphenyl-4-carboxylate(M6),6-(undec-10-enoyloxy)hexahyd-rofuo[3,2-b]furan-3-yl4’-(allyloxy)biphenyl-4-carboxylate(M7)and6-(undec-10-enoyloxy)hexah-ydrofuro[3,2-b]furan-3-yl4’-(undec-10-enoyloxy)biphenyl-4-carboxylate(Mg).M6is liquid crystal,M7and M8are non-liquid crystal Crosslinker. Different kinds of mesogenic monomers were grafted to linear polymethylhydrogensiloxanes. Especially, monomers and the six side-chain liquid crystalline polymers and liquid crystal elastomers were first prepared. The structures and properties of the obtained liquid crystalline monomers, crosslinking agent, LCPs and LCEs were investigated by FT-IR spectroscopy,1H-NMR spectroscopy, differential scanning calorimetry(DSC) and polarizing optical microscopy (POM) structure-property relationships were discussed in detail.The results indicate the structures are designed in accordance with the monomers.The monomers have melting point and cleaning point.They have series of liquid crystalline texture.M1,M2and M6are nematics;M3and M4are cholesteric;M5is smectic convert to nematic.P1,P2and P3series are cholesteric;P4,P5and P6series are smectic.Not only they have important theoreticalvalue, but also provide the development and application with technology support on liquid crystalline area.