Synthesis And Characterization Of New Esters Star-Shaped Side-Chain Liquid Crystalline Polymers

Liquid crystalline polymer is considered a new and superior material. And the aromatic ester-based liquid crystal polymer has been developed for several years. Macromolecules of these polymers show many kind of specific features. The star of aromatic ester-based liquid crystal polymer, as new type of polymer liquid crystals materials, has a complete different molecular structure from that of tradition rodlike molecule, which has important theory significance and potential application value. In this paper, on the basis of consult lots of reports, the thesis centered on3,5-dihydroxybenzoic acid, Gallic acid are synthesized many different star of aromatic ester-based liquid crystalline compounds, then liquid crystalline polysiloxone was prepared by grafting react ion of the monomer. In addition, the chemical structure of the monomer and polymer as confirmed by IR and1HNMR analysis, and the phase behavior was observed by DSC and optical polarized microcoly. These research works expanded the types of the SLCP, provided some theoretical bases in design and synthesis of SLCP for some specific properties, and can also establish foundations for the application study of new types of SLCP.In this dissertation, we will report the design and synthesis of the eight star of aromatic ester-based liquid crystal polymers, three kinds rodlike molecule liquid crystal polymers. Eight tar of aromatic ester-based liquid crystal polymers are4-[3,5-bis (formyl phenoxy ethoxy benzoyloxy benzoyloxy E)] benzoyloxy-4’-on allyloxy benzoyloxy benzene(M1),[3,5-bis (formyl phenoxy ethoxy benzoyloxy benzoyloxy E)] benzoyloxy benzoyloxy of allyloxy hexanediol diester(M2),4-[3,5-bis (nitro-benzoyloxy benzoyloxy E formyl phenoxy)] benzoyloxy-4’-on allyloxy benzoyloxy benzene(M3),[3,5-bis (nitro-benzoyloxy benzoyloxy E formyl phenoxy)] benzoyloxy benzoyloxy of allyloxy hexanediol diester(M4),4-[3,4,5-tris (phenoxy ethoxy benzoyloxy benzoyloxy formyl e)] benzoyloxy-4’-on allyloxy benzoyloxy benzene(M5),[3,4,5-tris (phenoxy ethoxy benzoyloxy benzoyloxy formyl e)] benzoyloxy benzoyloxy of allyloxy hexanediol diester(M6),4-[3,4,5-tris (phenoxy formyl nitro benzoyloxy benzoyloxy E)] benzoyloxy-4’-on allyloxy benzoyloxy benzene(M7),[3,4,5-tris (phenoxy formyl nitro benzoyloxy benzoyloxy E)] benzoyloxy benzoyloxy of allyloxy hexanediol diester(M8). Three kinds of Rod-like chiral monomer are4-allyloxy-phenoxy-formyl E benzoyloxy benzoyloxy cholesterol ester(M9),4-allyloxy benzoyloxy benzoyloxy nonyl phenoxy formyl ester cholesterol(M10),4-allyloxy benzoyloxy benzoyloxy menthol isopropyl ester(M11). By grafting copolymerization of monomers (M5and M9),(M7and M9),(M8and M9) to the main chain of poly (hydrogen methyl siloxane), three series of side-chain liquid crystalline polymers P1-P3are synthesized. To our knowledge, the obtained monomers and the polymers have never been reported up to now.The results show that all the monomers and side-chain polymers are liquid crystals except the M2, M4, M10and M11. M1, M3, M5, M6, M7and M8are thermal enantiotropic nematic liquid crystals. M9is thermal enantiotropic cholesteric liquid crystal. Polymers P1-P3are thermal enantiotropic liquid crystals. For the polymers P1and P2series of melting point Tg and the clearing point T; with the increase in star of aromatic ester-based liquid crystal polymers have higher trend, P3series of melting point Tg and the clearing point Ti with the increase in star of aromatic ester-based liquid crystal polymers have decreasing trend, and have wider range of liquid crystal.