Synthesis and characterization of halogen-containing ferroelectric liquid crystals and side chain liquid crystalline polymers

Abstract

2001) Synthesis and characterization of halogen-containing ferroelectric liquid crystals and side chain liquid crystalline polymers, Liquid Crystals, 28:3, 365-374, A new series of ferroelectric liquid crystals and side chain liquid crystalline polymers based on halogen-containing chiral centres has been synthesized. Chemical structures were analysed by NMR. Liquid crystal phases were characterized by diOE erential scanning calorimetry, optical polarizing microscopy, and X-ray diOE ractometry. The behaviour of the liquid crystalline phases was investigated as a function of spacer units and diOE ering terminal asymmetric moieties. It was found that phase transition temperatures decreased with increasing length of the oligooxyethylene spacer unit. DiOE ering terminal asymmetric moieties led to diOE ering mesophase phenomena. Furthermore, a wide temperature range (including room temperature) of a chiral smectic C phase was achieved.

Side-chain Liquid Crystal Polymers (SCLCP): Methods and Materials. An Overview

“…In the past, majority of side chain liquid crystal materials were made by two synthetic routes – free radical polymerization of acrylic type monomers, bearing mesogenic moieties [ 12 , 13 ] and hydrosilylation of mesogenic terminal alkenes with linear poly[(methylhydro)siloxanes], copolymers bearing alkylhydrosiloxane monomeric units [ 12 , 14 ] or polymer systems modified with reactive Si-H bonds [ 15 ]. These methods could be, in principle, applied only in synthesis of thermotropic SCLCP’s having different backbones, organic and rigid (acrylates) or purely inorganic, and flexible ones (polysiloxanes).…”

“…(Figure 16) [75]. All of them exhibited the chiral smectic C phase (for example T g 26 SmC* 139 Ch 160.5 I forX=Cl, n=3) except for the one containing bromine in the side chain.…”

Ferroelectric Polymers and Their Energy‐Related Applications

“…Since then great efforts have been placed on the synthesis of new ferroelectric liquid crystal polymers in terms of searching for new macromolecule backbones and mesogenic groups, as well as constructing copolymers with different side chain structures. For example, the ferroelectric liquid crystal polymers with backbones of polysiloxanes, polyethers, and polyesters have been developed . Also, side chains with more than one chiral center or even multiple types of side chain structures have been employed in creating the ferroelectric liquid crystal polymers .…”

Functional Photochromic Methylhydrosiloxane‐Based Side‐Chain Liquid‐Crystalline Polymers

“…Numerous review articles reveal the details and advantages of this method . The second often used method is the hydrosilylation reaction of mesogenic alkenes with linear poly[(methylhydrosiloxanes] (PMHS), leading to SCLCPs with highly flexible backbone . The flexible backbone ensures to obtain SCLCPs with a much lower glass transition temperature ( T g ) than those obtained from polyacrylates.…”