Synthesis And Properties Of Chiral Liquid Crystal Based On Borneol

Chiral liquid crystals have attracted more and more attention at present. Molecular chirality has a particularly remarkable influence on the macroscopic physical properties of liquid crystal systems. Introduction of a chiral molecule may be a helical structure of the liquid crystal molecules, so that the helical structure of the chiral liquid crystal has optical characteristics that do not have many of the conventional liquid crystal, such as optically selective reflection of polarized light, circular dichroism and the like. Such liquid crystal because of its unique optical, electrical properties and increasingly widespread attention. In this thesis, we synthesized a series of chiral liquid crystal monomers and side chain liquid crystalline polymers containing borneol and their structures and liquid crystal behaviors were identified.This thesis is divided into three parts. In the first part, we synthesized a series of chiral liquid crystal monomers called 4BOBnB(n=1-～10,12,14,16,18), using bornoel group as chiral primitives,-/-ArCOOArAr-/-as the rigid mesogenic core, succinic acid as the interval group, alkoxy group as the terminal group with the length varying. The effect of the length of terminal group on liquid crystal properties was discussed. During the heating process, liquid crystal monomers reveal oily streak texture and smectic TGBA texture. And during the cooling process, monomers show focal conic texture, fingerprint texture.and TGBA texture.In the second part, we synthesized a series of chiral liquid crystal monomers called 4BOBmAB(m=2-10,12,14,16,18), using bornoel group as chiral primitives,-/-ArCOOArAr-/-as the rigid mesogenic core, succinic acid as the interval group, acyloxy group as the terminal group with the length varying. The effect of the length of terminal group on liquid crystal properties was discussed. By testing the monomers, liquid crystal monomers reveal oily streak texture and smectic texture during the heating process. And during the cooling process, monomers show focal conic texture, fingerprint texture etc.In the third part, we synthesized a series of chiral liquid crystal monomers (M1, M2, M3, M4, M5, M6) using bornoel group as chiral primitives, a reactive alkene group as end group. A series of P1～P6 polymers were prepared by graft polymerization using PMHS as backbone. By testing the monomers we found that M1, M2, M3 present SmC* and focal conic texture in the heating race. And they all show focal conic texture and SmC* texture. Correspondingly M4. M5, M6 reveal oily streak texture partially during the heating time, correspondingly they present focal conic texture only.A series of P1～P6 polymers were prepared by graft polymerization using PMHS as backbone. P1～P6 show that this series of polymers present grandjean texture in the liquid crystal range. All liquid crystal monomers and polymers are thermotropic enantiotropic liquid crystal. Chiral nematic liquid crystal of Pi-P6 polymers are identified by POM and XRD.