Synthesis And Phase Behavior Of Schiff Basesfor The Guest-Host Liquid Crystal Displays

For the Guest-Host liquid crystal displays, the solubility of the dye gusts in the liquid crystal hosts is an important influencing factor for the effect of displays. In order to improve the solubility of the dyes, such as: azo dyes, anthraquinone dyes etc, in liquid crystals, we designed and synthesized of the series of Schiff base compounds that containing amide, and hope to obtain some of liquid crystal materials which will be good for Guest-Host liquid crystal displays.In this thesis, fifteen target molecules containing Schiff base and amide have been designed and synthesized. Their chemical structure are determined by 'HNMR, IR, and their mesomorphic properties have been studied by both DSC analysis and polarizing microscopy. The results show:1 These compounds show a higher thermostability.2 The melting points of a series of compounds show an odd-even effect, when the number of carbons of the terminal alkoxy is even number, the compounds have higher melting points.3 When the length of the flexible end-group is too short, the compounds show no mesomorphicphase.4 The enthalpy of isotropization exists the same tendency as theisotropization temperature and mesomorphic range to decrease with increasing number of carbons.5 The isotropization temperature increase when the number of carbons in amide linkage increase.6 When there is a branch line in the amide linkage, themesomorphicphase is hard to form.