Synthesis And Characterization Of Several Liquid Crystal Monomers And Chiral Liquid Crystalline Polymers

Chiral liquid crystal material due to its unique optical properties, such as the choice of optical reflection, thermochromism, ferroelectric, piezoelectric, etc, and because it maintained the cholesteric liquid crystal optical properties of the small molecule, while at the same time with the polymer excellent properties such as ease of processing, it has broad application prospects in nonlinear optics, fast optical switches, microelectronics and other fields. Directly to the current isosorbide as a chiral agent to isosorbide synthetic element with the liquid crystal monomer and the polymer has not been reported. In this thesis, design and synthesis of isosorbide containing motif of the novel chiral liquid crystal monomers and polymers, not only enriched the study of chiral liquid crystal compounds of the content, but also for our further synthetic piezoelectric and ferroelectric liquid crystal polymers and performance and application of research provides a basis.In this thesis, nine monomers M1～M9 were synthesized, which include four kinds of nematic phase monomer, five kinds of cholesteric phase monomer cholesteryl. P1 were prepared by graft polymerization of M2 and M9 using polymethylhydrosiloxane as backbone, P2 were prepared by graft polymerization of M4 and M9 using polymethylhydrosiloxane as backbone, and P3 were prepared by graft polymerization of M2 and M5 using polymethylhydrosiloxane as backbone.The structures and optical and thermodynamic properties of the obtained liquid crystalline monomers and polymers were investigated by rotation activity instrument, FT-IR spectroscopy, differential scanning calorimetry (DSC) and polarizing optical microscopy (POM).Results of experiments and analyses indicated that PolymersP1, P2, P3 series were cholesteric liquid crystals;The ranges of temperature of liquid crystalline phase of P1, P2 increased with increased of the chiral cholesteric monomer M9.The glassy state transition temperature of P1, P2 increased also.The clearing point increased at the same time. P3 series with increased of the chiral cholesteric monomer M5.The cholesteric Grandjean texture are also becoming more and more bright, and the glassy state transition temperature of P3 appear reduced after the first elevated temperature.P1, P2 andP3 series have excellent thermal stability and therefore have a certain applied value.