Synthesis and Mesomorphic Properties of New Chiral Liquid-Crystalline Diols

Abstract

Two series of new ferroelectric liquid-crystalline diols with 1,3-propandiol group connected by a flexible spacer to the mesogenic part of the molecule have been synthesized. Both series are laterally substituted by methyl, methoxy, or chlorine substituents in the meta position to the carboxylic group of the 4-alkoxybenzoate unit. Phases and phase-transition temperatures were determined by polarizing microscopy and Differential Scanning Calorimetry (DSC). Mesomorphic properties of the studied compounds are compared and the effect of lateral substitution is evaluated. These new series of diols are predestined for preparation of liquidcrystalline polyurethanes by bulk polymerization in the temperature range of the SmC Ã phase.

Thermotropic and lyotropic behaviour of new liquid-crystalline materials with different hydrophilic groups: synthesis and mesomorphic properties

“…A compound that carries a hexyloxy group and a pentyl spacer has been studied recently [27]; mesomorphic behaviour of this material was very similar to that of TL4 . Corresponding mesophases N* and SmC* were also observed for the chiral compound in [26] having the same molecular core as TL4 but a branched chiral alkoxy chain instead of the decyloxy group used for TL4 . The relation between the molecular structure and mesomorphic properties of these new multifunctional compounds with different structures is discussed.…”

“…This understanding is of high potential interest for challenging issues such as the organization of carbon nanotubes [17] or various nanoparticles [18] in a liquid-crystalline matrix. To reach the goal, several new multifunctional liquid-crystalline materials possessing either ethylene glycol units (denoted as TL1 and TL2 ) or a different number of hydroxy groups (denoted as TL3 and TL4 [26–28]) or both types of these hydrophilic groups together and an additional photosensitive azo group in the molecular core (denoted as TL5 ) have been designed, synthesized and studied (see Table 1 for the chemical structures). Compound TL4 with a decyloxy end group and a hexyl spacer was described in [28] along with a similar compound having a hexyloxy end group.…”

Rheological characterisation of a liquid-crystalline diol and its dependence with an applied electric field

“…The compound used for the present studies was originally predestined for the preparation of chiral liquid-crystalline polyurethanes [21] by means of bulk polymerisation [22].…”

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

“…For example, E–Z ( trans–cis ) isomerization takes place upon UV light irradiation in azobenzene derivatives possessing a NN moiety. Advanced examples of these systems are self‐assembling polymer systems exhibiting liquid crystalline (LC) behavior such as poly­siloxanes, polyacrylates, polybutadiene diols, and polyurethanes …”

“…The first one is the preparation of physical mixtures of the “guest” photochromic dopant molecules and the “host” LC poly­mer . The second, more efficient method is covalent bonding of the photoactive molecules (side‐chain monomers) to LC polymer, and finally in the third method, the photosensitive molecules are attached to the polymer matrix by weak non‐covalent hydrogen or ionic bonding. In the following, we will mainly focus on the second method in obtaining side‐chain liquid crystal polymers (SCLCPs).…”