Synthesis And Characterization Of Side-chain Liquid Crystalline Polymers Formed By Different Style Bonds

Side-chain liquid crystalline polymers (SLCPs), which liquid group situated on the side-chain of polymers, are new kinds of materials with broad, applied foreground and have attracted considerable attention and interest. SLCPs have been used in many kinds of fields, such as gas chromatography, the memorization and display of information. Besides, supramolecular liquid crystalline polymers have been another study focus gradually.And the supramolecular liquid crystalline polymers based on hydrogen bonds have been studied deeply, especially the side-chain supramolecular liquid crystalline polymers due to their design agility and broad functional applied foreground.In this dissertation, twelve monomers were synthesized, which include cholestery sebacate monoester(Mo),4-allyloxy-biphenyl-4-ethoxybenzonate(M1),4-(4-ethoxyl)benzocyl-4-(4-allyloxy)benzoyloxy hydroquinone diester(M2),10-(4-(4-allyloxy phenyl propionyloxy) hydroxybiphenyl)cholesterylsebacate(M3),6-(4-(4-allyloxy-phenyl-propionyloxy)hydroxyl biphenyl)cholesteryladipate(M4),4-[4-(10-undecylen-1-yloxy)]benzocyl pyridine(M5),4-(4-allyloxy)benzocyl pyridine(M6),4-(4-ethoxyl)benzocyl hydroxybiphenyl sebacate monoester (M7),4-(4-ethoxyl)benzocyl pyridine(m1),4-{4-[2-(4-allyloxy)benzocyl]ethoxyl}benzocyl pyridine(m2), cholestery pyridine sebacate(m3), cholestery pyridine adipate(m4).These monomers are liquid crystalline except m1 and m2. Different kinds of mesogenic monomers (including nematic monomers and cholesteric monomers) were grafted to linear polymethyl hydrogensiloxanes. So two series of SLCPs with different chemical structures and characters were synthesized. In addition, the complex, which were prepared by cholesteric monomers M0, nematic monomers M7 with SLCPs P6 in a single system of pyridine by self-assembly, exhibited liquid crystalline properties as P3 series of SLCPs. The structures and properties of the obtained liquid crystalline monomers and SLCPs were investigated by FT-IR spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and polarizing optical microscopy (POM). Their structure-property relationships were discussed in detail. All the obtained monomers and polymers except M0-M2, M7 were novel. The study of their synthesis and properties would enrich the fields of SLCPs materials and supramolecular LCPs, and provide academic foundation for their application in the future.Monomers M0,M3,M4,m3 and m4 were cholesteric liquid crystallines and exhibite oily streak texture and focal conic texture, which were the typical textures of cholesteric phase. The selective reflection within the range of the visible spectrum, can be easily observed by naked eye, which was the character of the cholesteric liquid crystal material. Monomers M1, M2, M5-M7 were nematic liquid crystallines and present the texture of droplets, schlieren etc. The monomers have excellent liquid crystalline properties. These three series of polymers were cholesteric liquid crystals except P1-1, P2-1, P3-1 which were nematic liquid crystallines.For P1 series, the corresponding melting point (Tm) and clearing point (Ti) decreased with increasing the content of M4. For P2 series, the corresponding glass transition temperature (Tg) decreased with increasing the content of M3. The results of TGA show that P1, P2 series of polymers have excellent stability, so they have high applied values. P3 series of polymers have wide ranges of temperature of liquid crystalline phase and present excellent liquid crystalline properties.