Synthesis Of Liquid Crystalline Elastomers Containing Fluorine Hydrocarbon Chains、Fluorobenzene And Chiral Groups

The fluorinated liquid crystals own low viscosity, high resistivity, rapid response, due to the introduction of the atom of fluoride. It’s suitable for film field effect transistors drive liquid crystal display. The fluorinated liquid crystals account for a very important position in display materials. Chiral liquid crystalline polymers (LCPs) were also a hotspot of liquid crystalline research domains at present time. Due to the helical supermolecular structure, chiral liquid crystalline owns unique photo-electrical property.In this paper, four liquid crystals and seven series of liquid crystal elastomers were synthesized.6-(undec-10-enoyloxy)hexahydrofuro[3,2-b]furan-3-yl4’-(4-(undec-10-enoyloxy) benzoyloxy)biphenyl-4-carboxylate(M1),6-(undec-10-enoyloxy)hexahydrofuro[3,2-b]furan-3-yl4’-(4-(allyloxy)benzoyloxy)biphenyl-4-carboxylate(M2),2-(2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-pent adecafluorooctanoyloxy)ethyl4’-(4-(undec-10-enoyloxy)benzoyloxy)biphenyl-4-carboxylate(M3),4-(2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-pentadecafluorooctanoyloxy)butyl4’-(4-(undec-10-enoylo xy)benzoyloxy)biphenyl-4-carboxylate(M4). M1and PMHS for grafting polymerization, get the Pi series elastomers. M2and PMHS for grafting polymerization, get the P2series elastomers.4’-(undec-10-enoyloxy)biphenyl-4-yl4-(allyloxy)-2-fluorobenzoate(J2) and PMHS for grafting polymerization, get the P3series elastomers. J2and M4for grafting polymerization with PMHS, get the P4series elastomers. M1and M3for grafting polymerization with PMHS, get the P5series elastomers. M2and M4for grafting polymerization with PMHS, get the P6series elastomers.4’-(undec-10-enoyloxy)biphenyl-4-yl4-(allyloxy)-2-fluorobenzoate(J1) and M3for grafting polymerization with PMHS, get the P7series elastomers.The structures and properties of the obtained LC monomers, crosslinking agent, clastomers were investigated by FT-IR spectroscopy,1H-NMR spectroscopy, differential scanning calorimetry (DSC), and polarizing optical microscopy (POM). The results show that: the chemical structure of the synthesized monomers are consistent with the molecular design. And they exhibit good liquid crystallinity. Monomer M1in warming and cooling process both showed oily streak texture, It’s cholesteric crystal. Monomer M2and crosslinking agent J1are typical smectic-nematic crystal. Monomer M3, M4and crosslinking agent J2are nematic crystal. Elastomers P3series in warming and cooling process both showed the droplet texture. They are nematic phase crystal elastomers. Elastomers P1-P2series and P4-P7series belong to smectic liquid crystal elastomers. Chemical crosslinking limits the molecular chain sports, the Tg of polymers increased, the T; of polymers decreased. This paper discusses the effect of elastomers by the type and content of crosslinking agent.