Synthesis And Properties Of V-shaped Liquid Crystalline Polymers

V-shaped liquid crystal is also called banana-shaped liquid crystal or bow liquid crystal Because V-shaped liquid crystal molecules can polar arrangement and causes the chiral supramolecular chiral behavior, it can show a number of different liquid crystal phases, exhibit ferroelectric, anti-ferroelectric and ferromagnetic properties, making it have a wide range of applications in the photoelectric and other fields. In recent years, more and more people joined the V-shaped liquid crystal research ranks. In this paper, on the basis of consult lots of reports, by means of the synthesis of three type of thirteen kinds of liquid crystal (eleven kinds of V-shaped liquid crystal and two chiral liquid crystal), two corresponding series of LCPs. The structures of the synthesized monomers are confirmed by infrared spectroscopy (FT-IR) and nuclear magnetic resonance(1H-NMR) spectroscopy. The thermal properties of these polymers have been investigated using differential scanning calorimetry (DSC), polarizing optical macroscopic (POM), and thermogravimetric analysis (TGA).The main context are as follows:The first type of V-shaped liquid crystal is use m-Phthalic acid as the center. They are: 1-(4-allyloxybenzoyloxy-4-phenyl)-3-(4-ethoxybenzoyloxy-4-phenyl) isophthalate (M1), 1-(4-allyloxybenzoyloxy-4-biphenyl)-3-(4-ethoxybenzoyloxy-4-phenyl) isophthalate (M2), 1-(4-allyloxybenzoyloxy-4-biphenyl)-3-(4-nitrobenzoyloxy-4-phenyl) isophthalate (M3), 1-(4-undeceneacyloxy-4-biphenyl)-3-(4-nitrobenzoyloxy-4-phenyl) isophthalate (M4), 1-(4-nitrobenzoyloxy-4-biphenyl)-3-(4-allyloxybenzoyloxy-4-phenyl) isophthalate (M5), 1-(4-ethoxybenzoyloxy-4-biphenyl)-3-(4-allyloxybenzoyloxy-4-phenyl) isophthalate (M6), M4 is thermal unilateral liquid crystals, the rest are thermal enantiotropic nematic liquid crystals. Their Ti are above 200℃ the liquid crystal range is very broad.The second type of V-shaped liquid crystal is use m-Dihydroxy benzene as the center. Which are:1-(4-allyloxybenzoyloxy)-3-(4-ethoxybenzoyloxy) phenoxyformyl amylbenzoyloxy benzene (M7), 1-(4-undeceneacyloxy benzoyloxy)-3-(4-ethoxybenzoy-loxy) phenoxyformyl amylbenzoyloxy benzene (Mg), 1-(4-allyloxybenzoyloxy)-3-(4- nitrobenzoyloxy) phenoxyformyl amylbenzoyloxy benzene (M9), 1-(4-undeceneacyloxy benzoyloxy)-3-(4-nitrobenzoyloxy) phenoxyformyl amylbenzoyloxy benzene (M10), 1-(4-ethoxybenzoyloxy)-3-(4-allyloxybenzoyloxy) phenoxyformyl amylbenzoyloxy benzene (M11). They are thermal enantiotropic nematic liquid crystals. Tm is basically about 72℃ the heating liquid crystal range in the in the range of 20～60℃, the cooling liquid crystal range in the range of 21～116℃.The third type is chiral liquid crystal, which are 4-allyloxybenzoate cholesteryl ester (Ma), 4-undecene acyloxy acid cholesteryl ester (Mb).The Pi series is systhesised by crystal V-shaped crystal M1 and chiral liquid crystal Mb connecting to PMHS with vavies contents. The P2 series is systhesised by crystal V-shaped crystal M7 and chiral liquid crystal Ma connecting to PMHS with vavies contents.The results show that they all thermal enantiotropic nematic liquid crystals. Their thermal stability is well, the decomposition temperature is more than 300℃. The Ti with the increasing of V-shaped crystals are both showing a decreasing trend.