Phase Diagrams and Phase Separation Dynamics in Mixtures of Side-Chain Liquid Crystalline Polymers and Low Molar Mass Liquid Crystals

1996 ◽  
Vol 29 (3) ◽  
pp. 1051-1058 ◽  
Author(s):  
Hao-Wen Chiu ◽  
Zheng Long Zhou ◽  
Thein Kyu ◽  
Leonorina G. Cada ◽  
L.-C. Chien
Keyword(s):  
Phase Separation ◽  
Liquid Crystals ◽  
Phase Diagrams ◽  
Liquid Crystalline ◽  
Molar Mass ◽  
Liquid Crystalline Polymers ◽  
Side Chain ◽  
Crystalline Polymers

Phase behavior of side-chain liquid-crystalline polymers containing biphenyl mesogens with different spacer lengths synthesized via miniemulsion polymerization

2016 ◽  
Vol 7 (29) ◽  
pp. 4736-4750 ◽  
Author(s):  
Ehsan Mehravar ◽  
Amaia Iturrospe ◽  
Arantxa Arbe ◽  
José M. Asua ◽  
Jose R. Leiza
Keyword(s):  
Phase Behavior ◽  
Liquid Crystalline ◽  
Molar Mass ◽  
Miniemulsion Polymerization ◽  
Liquid Crystalline Polymers ◽  
Side Chain ◽  
High Molar Mass ◽  
Crystalline Polymers

High molar mass SCLCPs were synthesized by miniemulsion polymerization, and the phase behavior of the polymers was investigated by a combination of DSC, PLM, SAXS and WAXS.

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

2001 ◽  
Vol 28 (3) ◽  
pp. 365-374 ◽  
Author(s):  
Ging-Ho Hsiue ◽  
Yi-An Sha ◽  
Shih-Jung Hsieh ◽  
Ru-Jong Jeng ◽  
Wen-Jang Kuo
Keyword(s):  
Liquid Crystals ◽  
Liquid Crystalline ◽  
Liquid Crystalline Polymers ◽  
Side Chain ◽  
Synthesis And Characterization ◽  
Ferroelectric Liquid Crystals ◽  
Crystalline Polymers

Rheology of Liquid-Crystalline Polymers

2007 ◽  
Author(s):  
Chang Dae Han
Keyword(s):  
Liquid Crystals ◽  
Polymer Chain ◽  
Liquid State ◽  
Liquid Crystalline ◽  
Main Chain ◽  
Liquid Crystalline Polymers ◽  
Point Of View ◽  
Side Chain ◽  
Crystalline Polymers ◽  
Molecular Features

Liquid crystals (LCs) may be divided into two subgroups: (1) lyotropic LCs, formed by mixing rigid rodlike molecules with a solvent, and (2) thermotropic LCs, formed by heating. One finds in the literature such terms as mesomorphs, mesoforms, mesomorphic states, and anisotropic liquids. The molecules in LCs have an orderly arrangement, and different orders of structures (nematic, smectic, or cholesteric structure) have been observed, as schematically shown in Figure 9.1. The kinds of molecules that form LCs generally possess certain common molecular features. The structural characteristics that determine the type of mesomorphism exhibited by various molecules have been reviewed. At present, our understanding of polymeric liquid crystals, often referred to as liquid-crystalline polymers (LCPs), is largely derived from studies of monomeric liquid crystals. However, LCPs may exhibit intrinsic differences from their monomeric counterparts because of the concatenation of monomers to form the chainlike macromolecules. The linkage of monomers inevitably means a loss of their translational and orientational independence, which in turn profoundly affects the dynamics of polymers in the liquid state. These intramolecular structural constraints are expressed in the flexibility of the polymer chain. Generally speaking, the chemical constitution of the monomer determines the flexibility and equilibrium dimensions of the polymer chain (Gray 1962). Figure 9.2 illustrates the variability of chain conformation (flexible chain, semiflexible chain, and rigid rodlike chain) forming macromolecules. Across this spectrum of chain flexibility, the persistence in the orientation of successive monomer units varies from the extreme of random orientation (flexible chains) to perfect order (the rigid rod). Hence, efforts have been made to synthesize LCPs that consist of rigid segments contributing to the formation of a mesophase and flexible segments contributing to the mobility of the entire macromolecule in the liquid state (Ober et al. 1984). From the point of view of molecular architecture, as schematically shown in Figure 9.3, two types of LCP have been developed: (1) main-chain LCPs (MCLCPs), having the monomeric liquid crystals (i.e., mesogenic group) in the main chain of flexible links, and (2) side-chain LCPs (SCLCPs), having the monomeric liquid crystals attached, as a pendent side chain, to the main chain.

Phase transitions in narrow-molar-mass samples of side-chain liquid-crystalline polymers: molar-mass dependence

Polymer ◽  
1992 ◽  
Vol 33 (20) ◽  
pp. 4352-4357 ◽  
Author(s):  
U.W Gedde ◽  
H Jonsson ◽  
A Hult ◽  
V Percec
Keyword(s):  
Phase Transitions ◽  
Liquid Crystalline ◽  
Molar Mass ◽  
Liquid Crystalline Polymers ◽  
Side Chain ◽  
Mass Dependence ◽  
Crystalline Polymers

Liquid crystalline polymers: self-organization and assembly

1993 ◽  
Vol 344 (1672) ◽  
pp. 403-417 ◽  
Keyword(s):  
Liquid Crystals ◽  
Self Assembly ◽  
Liquid Crystalline ◽  
Liquid Crystalline Polymers ◽  
Side Chain ◽  
Simple Liquid ◽  
Crystalline Polymers ◽  
Nematic Order ◽  
Nematic State ◽  
Chain Conformations

Liquid crystal forming monomers, typically rods, can be polymerized to form long mesogenic molecules. In contrast to simple rods, these polymers often have internal degrees of freedom so that they display the subtle behaviour of both high polymers and simple liquid crystals. They can have the rod elements either concatenated as a back-bone to give main chain (MC), or pendant to a back-bone to give side chain (SC) liquid crystals, or both. The physics unique to liquid crystalline polymers (LCPS) comes from their shape being dependent on the state of nematic order. Simple systems remain molecular rods (or disks) on ordering whereas a chain extends or flattens (depending on whether or not the nematic order is prolate or oblate). New phenomena as a result of this occur in situations as disparate as networks and, it is predicted, in dielectric response. We examine both SC and MC LCPS and the mechanisms by which they order lyotropically (in solution) and therm otropically (in the melt). Various types of models will be discussed in general and then restricted to the therm otropic case, lyotropic systems being discussed in Lekkerkerker & Vroege (this volume). The transition to the ordered state is first order as in simple nematics. The main characteristics of this state are modified chain conformations and, additionally for side chain polymers, transitions between various novel competing nematic states. A form of self-assembly that is a delicate function of the nematic order is observed in transesterifying LCPS. The number of chain ends is conserved but material exchanged between chains according to whether they are in the isotropic or nematic state. We review a model of this type of self-assembly.

Synthesis and Properties of Comb-Like Liquid Crystalline Polymers with Electrooptically Active Mesogenic Side Groups

1989 ◽  
Vol 175 ◽  
Author(s):  
M. Maeda ◽  
R.S. Kumar ◽  
A. Blumstein ◽  
S.K. Tripathy ◽  
P. Sixou ◽  
...  
Keyword(s):  
Phase Diagrams ◽  
Polymer Chain ◽  
Liquid Crystalline ◽  
Liquid Crystalline Polymers ◽  
Side Chain ◽  
Crystalline Polymers ◽  
Donor Acceptor

AbstractIn an attempt to synthesize side chain liquid crystalline polymers containing NLO active moieties, a number of psubstituted aromatic azomethine phenols with donor-acceptor substituents such as N≡C and NO2 were prepared and incorporated into a polymer chain as side groups.Liquid crystalline properties of intermediate compounds composed of such moieties were explored separately and in mixtures. Phase diagrams were established. These intermediate compounds of M2C8 and M5C8 show interesting mesogenic properties.Methacrylic esters with such moieties were also synthesized. Homopolymer and copolymer systems with donor-acceptor substituents were obtained. Such copolymers also display liquid crystalline properties.

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