Synthesis And Properties Of Main-chain And Side-chain Liquid Crystalline Ionomers

Liquid crystalline ionomers (LCIs) combine the basic features of liquid crystalline polymers (LCPs) with good physical properties of ionomers, and they have unique optical, electromagnetical and good mechanical properties and chemical stability. Study on new LCIs has very important theory purpose and potential application in the fields of optics, message, military, print, and composite materials etc. Because of strong ionic action of sulfonic groups, the polarity and mesogenic properties of LCPs are shown when a little ion is introduced into the polymers. Compared to other type of LCIs, the LCIs containing sulfonic groups have important theory purpose and application. Because of the preparation of the LCIs containing sulfonic groups is more difficult, the research is little reported. Therefore, this study has important theory and application, and also provides theoretical basis and novel thought to investigate and exploit special type of high-performance composite materials.In this dissertation, four monomers (M0-M3)and a ionic monomer Mso3H were prepared, which include terephthalic acid-4-carboxybenzolbiester(M0),4-allyloxy-4'-(4-methyl benzoic acid)hydrochinone(M1),4-allyloxy-4'-(4-propylphenylformic acid)p-biphenylate (M2),4-allyloxy-4'-(4-pentylphenylformic acid)p-biphenylate (M3),4-allyloxy-4'-phenylazobenzene sulfonic(Mso3H).The main chain liquid crystal ionic was synthesized according to M0,brittle yellow(BY),decatyl glycol and laurohydro glycol by. fasculated. we have got side chain liquid crystal ionic to based on M2,M3,MSO3H and PMHS which were graft polymerized. The side chain liquid crystal ionic (SCLCI2) was fabricated by sulfonation reaction to M3 and PMHS which were graft polymerized. It did not report that we have synthesized ionomers in-country. The structure and performance of intermediates,monomers and polymers were analyzed by FT-IR,polarimeter,POM,DSC and TGA. The structure and solicit contributions of monomers affect to temperature of phases types of phases and texture of liquid crystals were discussed.It were presented that the monomers(M0,M1,M2,M3) and liquid crystalline ionomers (LCls) are were nematic phases. The monomers present the texture of droplets,schlieren,thread-like,broken focal conic etc. According to the analysis of DSC, the liquid crystal has the transition of melt ability and difference phases. The main chain liquid crystal inomers of Tg is augmented and Tm is fell according to the concentration of ionic increased, at the same time, the Ti is augmented and then fell. The SCLCI1 of Tg is augmented then fell and the range of liquid crystal is broadened. The SCLCI2 of Tg is augmented then fell and the range of liquid crystal is broaden.The liquid crystal property of SCLCI2 is faded away when the mol concentration of ionic arrive at 8%.