Synthesis And Characterization Of Liquid Crystals And Self-assembled Polymers Containing Chiral And Ionic Units

Liquid Crystalline Ionomers(LCIs)are the kinds of polymers which contain ions and show liquid crystalline behaviors.They are a class of ionic polymers developed on the basis of liquid crystal polymers and ionomers.LCIs show unique optical and electromagnetic properties,favorable mechanical properties,and good chemical stability.As a kind of new functional polymer materials,LCIs are not only used in many applications such as physics,chemistry,materialogy,electronics and so on;but also have potential application prospect in the field of the information domain,military,printing,optics,composite material and membrane materials.In this dissertation,three monomers were synthesized,which include cholesteryl 2-bromopropanoate(M1),cholesteryl 4-((2-bromopropanoyl)oxy)benzoate(M2)and cholesteryl 4-((2-bromopropanoyl)oxy)-2-fluorobenzoate(M3).Three series of ionic liquid crystals were synthesized by a salification reaction of N-alkylimidazole(i.e.1-methylimidazole,l-isopropylimidazole and 1-butylimidazole)and the aryl bromides(i.e.M1,M2,and M3).Three series of liquid crystal polymers(Pa,Pb,and Pc)were also synthesized by a salification reaction of polyethyleneimine and the aryl bromides.Furthermore,nine series of liquid crystalline ionomers(P1,P2,P3,P4,P5,P6,P7,P8,and P9)were respectively synthesized by a ion exchange reaction using trifluoroacetic acid,fluoroboric acid and hexafluorophosphoric acid.Especially,all the synthesized liquid crystalline monomers,liquid crystal polymers and ionomers in this dissertation have not been reported in previous literature,thus the study in this dissertation is original.The chemical structures of the synthesized liquid crystalline monomers,liquid crystal polymers and LCIs were characterized by FT-IR,1H-NMR.And their liquid crystalline behaviors such as thermal properties and mesogenic textures were studied by use of differential scanning calorimetry(DSC),polarized optical microscopy(POM)and so on.The research in this dissertation has important theory and real meaning.Moreover,it provides some theory basis and some necessary technical supports for further application of LCIs.