Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Thermotropism

Other interesting Langmuir monolayer systems include spread thermotropic liquid crystals where a foam structure forms on expansion from a collapsed state [23]. Spread monolayers of clay dispersions form a layer of overlapping clay platelets that can be subsequently deposited onto solid substrates [24]. [Pg.542]

A unique but widely studied polymeric LB system are the polyglutamates or hairy rod polymers. These polymers have a hydrophilic rod of helical polyglutamate with hydrophobic alkyl side chains. Their rigidity and amphiphilic-ity imparts order (lyotropic and thermotropic) in LB films and they take on a F-type stmcture such as that illustrated in Fig. XV-16 [182]. These LB films are useful for waveguides, photoresists, and chemical sensors. LB films of these polymers are very thermally stable, as was indicated by the lack of interdiffusion up to 414 K shown by neutron reflectivity of alternating hydrogenated and deuterated layers [183]. AFM measurements have shown that these films take on different stmctures if directly deposited onto silicon or onto LB films of cadmium arachidate [184]. [Pg.561]

Ruths M, Steinberg S and Israelachvili J N 1996 Effects of confinement and shear on the properties of thin films of thermotropic liquid crystal Langmuir M 6637-50... [Pg.1749]

Liquid crystal phases can be divided into two classes. Thermotropic liquid crystal phases are fonned by pure... [Pg.2542]

Hamley I W, Garnett S, Luckhurst G R, Roskilly S J, Pedersen J S, Richardson R M and Seddon J M 1996 Orientational ordering in the nematic phase of a thermotropic liquid crystal A small angle neutron scattering study J. Chem. Phys. 104 10 046-54... [Pg.2568]

Vertogen G and de Jeu W H 1988 Thermotropic Liquid Crystals, Fundamentals (Heidelberg Springer). [Pg.2572]

In the late 1980s, new fully aromatic polyester fibers were iatroduced for use ia composites and stmctural materials (18,19). In general, these materials are thermotropic Hquid crystal polymers that are melt-processible to give fibers with tensile properties and temperature resistance considerably higher than conventional polyester textile fibers. Vectran (Hoechst-Celanese and Kuraray) is a thermotropic Hquid crystal aromatic copolyester fiber composed of -hydroxyben2oic acid [99-96-7] and 6-hydroxy-2-naphthoic acid. Other fully aromatic polyester fiber composites have been iatroduced under various tradenames (19). [Pg.325]

Rigid-rod polymers are often Hquid crystalline polymers classified as lyotropic, such as the aramids Nomex and Kevlar, or thermotropic Hquid crystalline polymers, such as Vectran. [Pg.64]

In 1975, the synthesis of the first main-chain thermotropic polymers, three polyesters of 4,4 -dihydroxy-a,a -dimethylbenzalazine with 6, 8, and 10 methylene groups in the aHphatic chain, was reported (2). Shortly thereafter, at the Tennessee Eastman Co. thermotropic polyesters were synthesized by the acidolysis of poly(ethylene terephthalate) by/ -acetoxybenzoic acid (3). Copolymer compositions that contained 40—70 mol % of the oxybenzoyl unit formed anisotropic, turbid melts which were easily oriented. [Pg.64]

Industrial Thermotropic LGPs. Vectran, poly(6-hydroxy-2-naphthoic acid- o-4-hydroxybenzoic acid) [81843-52-9] is currendy the only thermotropic fiber which is commercially available (13). Vectran is synthesized by the melt acidolysis of/ -acetoxybenzoic acid and 6-acetoxy-2-naphthoic acid. [Pg.67]

Properties. As prepared, the polymer is not soluble in any known solvents below 200°C and has limited solubiUty in selected aromatics, halogenated aromatics, and heterocycHc Hquids above this temperature. The properties of Ryton staple fibers are in the range of most textile fibers and not in the range of the high tenacity or high modulus fibers such as the aramids. The density of the fiber is 1.37 g/cm which is about the same as polyester. However, its melting temperature of 285°C is intermediate between most common melt spun fibers (230—260°C) and Vectran thermotropic fiber (330°C). PPS fibers have a 7 of 83°C and a crystallinity of about 60%. [Pg.70]

Liquid crystals may be divided into two broad categories, thermotropic and lyotropic, according to the principal means of breaking down the complete order of the soHd state. Thermotropic Hquid crystals result from the melting of mesogenic soHds due to an increase in temperature. Both pure substances and mixtures form thermotropic Hquid crystals. In order for a mixture to be a thermotropic Hquid crystal, the different components must be completely miscible. Table 1 contains a few examples of the many Hquid crystal forming compounds (2). Much more is known about calamitic (rod-Hke) Hquid crystals then discotic (disk-like) Hquid crystals, since the latter were discovered only recendy. Therefore, most of this section deals exclusively with calamities, with brief coverage of discotics at the end. [Pg.190]

Discotic Phases. Molecules which are disk-shaped rather than elongated also form thermotropic Hquid crystal phases. Usually these molecules have aromatic cores and six lateral substituents, although the predominance of six lateral substituents is solely historical molecules with four lateral substituents also can form Hquid crystal phases. Although the flatness of these molecules creates a steric effect promoting alignment of the normal to the disks, the fact that disordered side chains are also necessary for the formation of these phases (as is often the case for Hquid crystallinity in elongated molecules) should not be ignored. [Pg.195]

Some molecules ia a solvent form phases with orientational and/or positional order. In these systems, the transition from one phase to another can occur due to a change of concentration, so they are given the name lyotropic Hquid crystals. Of course temperature can also cause phase transitions ia these systems, so this aspect of thermotropic Hquid crystals is shared by lyotropics. The real distinctiveness of lyotropic Hquid crystals is the fact that at least two very different species of molecules must be present for these stmctures to form. [Pg.196]

A Hquid crystal compound in more cases than not takes on more than one type of mesomorphic stmcture as the conditions of temperature or solvent are changed. In thermotropic Hquid crystals, transitions between various phases occur at definite temperatures and are usually accompanied by a latent heat. [Pg.197]

G. Vertogen and W. H. dejeu. Thermotropic Eiquid Cystals, Fundamentals, Spriuger-Vedag, Berlin, 1988. [Pg.205]

Naphthalenedicarboxylic Acid. This dicarboxyhc acid, a potential monomer in the production of polyester fibers and plastics with superior properties (105), and of thermotropic Hquid crystal polymers (106), is manufactured by the oxidation of 2,6-dialkylnaphthalenes (107,108). [Pg.503]

Thermotropic polycarbonates have been prepared from mixtures of 4,4 -dihydroxybiphenyl and various diphenols (10). Nematic melts were found for copolycarbonates prepared from methyfliydroquiaone, chlorohydroquiaone, 4,4 -dihydroxydiphenyl ether, and 4,4 -dihydroxybenzophenone. Slightly crystalline polycarbonates have been prepared from mixtures of hydroquinone and BPA (T = 154°C, =313°C, AH = 11.0 J/g (2.63 cal/g)), and... [Pg.280]

Similady, hquid-crystal polymers exhibit considerable order in the hquid state, either in solution (lyotropic) or melt (thermotropic). When crystallized from solution or melt, they have a high degree of extended-chain crystallinity, and thus have superior mechanical properties. Kevlar (Du Pont) is an aromatic polyamide (atamid) with the repeating unit designated as (2). It is spun into... [Pg.433]

The thermotropic Hquid-crystal polyester Vectra A (Hoechst-Celanese) is reported to have the repeating units (3) and (4) and Xydar (Dartco) the repeating units (5) and (3). [Pg.433]

Licjuid Crystals. Ferroelectric Hquid crystals have been appHed to LCD (Uquid crystal display) because of their quick response (239). Ferroelectric Hquid crystals have chiral components in their molecules, some of which are derived from amino acids (240). Concentrated solutions (10—30%) of a-helix poly(amino acid)s show a lyotropic cholesteric Hquid crystalline phase, and poly(glutamic acid ester) films display a thermotropic phase (241). Their practical appHcations have not been deterrnined. [Pg.297]


See other pages where Thermotropism is mentioned: [Pg.2543]    [Pg.316]    [Pg.984]    [Pg.984]    [Pg.984]    [Pg.984]    [Pg.531]    [Pg.64]    [Pg.64]    [Pg.490]    [Pg.188]    [Pg.190]    [Pg.190]    [Pg.197]    [Pg.197]    [Pg.198]    [Pg.199]    [Pg.201]    [Pg.201]    [Pg.204]    [Pg.205]    [Pg.293]    [Pg.306]    [Pg.306]    [Pg.306]    [Pg.451]    [Pg.469]    [Pg.90]   
See also in sourсe #XX -- [ Pg.63 ]




SEARCH



1:1:1 alternating thermotropic

Aromatic thermotropic

Blends with Thermotropic Liquid Crystalline Polyesters (TLCP)

Cellulose thermotropic mesophases

Chain Thermotropic Liquid-Crystalline Polymers

Chiral thermotropic liquid crystal

Chiral thermotropic liquid crystal main chain

Chiral thermotropic liquid crystal polymers

Chiral thermotropic liquid crystal side chain

Chiral thermotropic polyesters based

Cholesteric mesophase, thermotropic liquid

Cholesteric mesophase, thermotropic liquid crystals

Cholesteric phase thermotropic polymers

Cholesteric phase, thermotropic liquid crystals

Cholesterol polymers, thermotropic

Columnar mesophases thermotropic liquid crystals, nematic discotic

Columnar phases, thermotropic liquid crystals

Computer simulations thermotropic liquid crystals

Copolyesters thermotropic type

Cubic phases thermotropic behaviour

Cubic thermotropic

Description Thermotropic liquid-crystalline polymer

Development of Thermotropic Polyesters

Discotic liquid crystals thermotropic mesophase

Discotic thermotropic polymers

Electrical properties, thermotropic

Electrical properties, thermotropic liquid crystal polymers

Electron microscopy of thermotropic

Electron microscopy of thermotropic copolyesters

Enthalpy, thermotropic liquid crystals

Enthalpy, thermotropic liquid crystals transition

Entropy, thermotropic liquid crystals

Expansion coefficients, thermotropic liquid

Flexible-chain polymers thermotropic

Formation of thermotropic mesophase

Glass transition temperature thermotropic liquid crystal polymer

Helical structures thermotropic

Injection molded thermotropic copolyester

Intermittent Shear Flow of Thermotropic Main-Chain LCPs

Isotropic-nematic phase transition thermotropic liquid crystals

Linear thermotropic polymers

Linear thermotropic polymers structure

Liquid crystalline mesophases thermotropic

Liquid crystalline polymeric thermotropic

Liquid crystalline polymers thermotropic

Liquid crystalline polymers thermotropic properties

Liquid crystalline state thermotropic

Liquid crystals thermotropic structures

Liquid crystals thermotropic systems

Liquid crystals thermotropic, hydrogen bonding

Liquid thermotropic

Liquid thermotropic phase

Liquid, definition thermotropic

Longitudinal thermotropic polymers

Maier-Saupe theory, thermotropic liquid

Maier-Saupe theory, thermotropic liquid crystals

Main-chain thermotropic liquid-crystalline

Mechanical properties thermotropic liquid crystal polymer

Mesogens thermotropic liquid crystals

Mesophase Identification in Thermotropic Polymers

Mesophase reactions, thermotropic

Mesophases thermotropic liquid crystals

Molecular dynamics thermotropic liquid crystals

Molecular modeling thermotropic liquid crystals

Monomeric thermotropics

Monomers thermotropic transitions

Morphology of thermotropic longitudinal polymer liquid crystals

NMR Studies of Thermotropic Polymers

NMR studies of local dynamics in side chain thermotropic polymers

NMR studies of orientational and conformational order in discotic thermotropic polymers

NMR studies of orientational and conformational order in longitudinal thermotropic polymers

NMR studies of orientational and conformational order in side chain thermotropic polymers

Naphthalene thermotropic

Naphthalene thermotropic polyesters

Naphthalene thermotropic polymers

Nematic discotic mesophase thermotropic cholesterics

Nematic discotic mesophase thermotropic liquid crystals

Nematic mesophase thermotropic

Nematic phase thermotropic polymers

Noel Side-Group Thermotropic Liquid-Crystalline Polymers

Of thermotropic main chain polymer liquid

Of thermotropic main chain polymer liquid crystals

Onsager theory, thermotropic liquid crystals

Order parameters, thermotropic liquid crystals

Orientational dynamics thermotropic liquid crystals

Packing thermotropic nematics

Phase transition dynamics thermotropic liquid crystals

Phase transition thermotropic

Phospholipids thermotropic phase transitions

Poly , thermotropic liquid crystalline

Poly , thermotropic liquid crystalline properties

Polyamides thermotropism

Polyesters thermotropic type

Polyether thermotropic

Polyimides thermotropic liquid-crystalline

Polymer thermotropic main-chain liquid crystal

Polymers displaying thermotropic

Polymers, liquid crystalline thermotropic type synthesis

Polymorphism in thermotropic liquid crystals

Polymorphism thermotropics

Rheological Behavior of Thermotropic Main-Chain LCPs

Rheological Behavior of Thermotropic Side-Chain LCPs

Rheological properties of thermotropic liquid crystalline polymers

Rheology thermotropic polymer liquid

Shear viscosity, thermotropic liquid crystals

Side-Chain Thermotropic Liquid Crystal Polymers

Side-Group Thermotropic Liquid-Crystalline Polymers

Side-chain thermotropic polymers

Smectic membranes thermotropic

Smectic phases thermotropic liquid crystals

Smectic thermotropic

Solid state physics of thermotropic

Solid state physics of thermotropic polyesters

Solvents, thermotropic liquid crystals

Studies of Thermotropics

Subject thermotropic

Switches, thermotropic liquid crystal

Switches, thermotropic liquid crystal polymers

Synthesis of thermotropic main chain LCPs

Temperature dependence thermotropic liquid crystals

Thermotropic

Thermotropic Behavior of Side-Chain Liquid Crystalline Block Copolymers

Thermotropic Chiral Mesophases

Thermotropic Cubic Phases

Thermotropic LC properties

Thermotropic LCPs

Thermotropic LCPs crystal polymer

Thermotropic LCPs crystalline polymers

Thermotropic LCPs processing

Thermotropic Liquid Crystal Polymer Reinforced Polyesters

Thermotropic Liquid Crystals Based on Planar Ion Pairs

Thermotropic Liquid-Crystalline Aliphatic Polyimides

Thermotropic Mesophases Formed by Achiral Rod-Like Molecules

Thermotropic PLCs

Thermotropic SCLCP

Thermotropic SmAs

Thermotropic aliphatic-aromatic

Thermotropic aliphatic-aromatic polyesters

Thermotropic amphiphilic systems

Thermotropic and Lyotropic Liquid Crystals

Thermotropic and Lysotropic Mesomorphism of Phospholipids

Thermotropic and lyotropic phase behavior of lipids

Thermotropic aromatic copolyesters with

Thermotropic aromatic poly

Thermotropic aromatic poly ester-amides)

Thermotropic aromatic polyesters

Thermotropic behaviors

Thermotropic calamitic

Thermotropic calamitic liquid crystals

Thermotropic cellulose derivatives

Thermotropic cellulose liquid crystals

Thermotropic cellulosics

Thermotropic chiral nematics

Thermotropic cholesteric liquid crystalline

Thermotropic cholesteric liquid crystalline polymers

Thermotropic cholesterics

Thermotropic cholesterol

Thermotropic cholesterol-containing liquid

Thermotropic classical

Thermotropic columnar phases, liquid crystalline

Thermotropic copoly

Thermotropic copolyester

Thermotropic copolyesters

Thermotropic copolyesters electron microscopy

Thermotropic copolyesters properties

Thermotropic crystalline polymers

Thermotropic discotic

Thermotropic effect

Thermotropic ferrocene

Thermotropic fibers

Thermotropic hquid-crystalline polymer

Thermotropic hydrogen bonded compounds

Thermotropic instabilities

Thermotropic lipid transitions

Thermotropic liquid crystal aromatic

Thermotropic liquid crystal aromatic copolyesters

Thermotropic liquid crystal phases

Thermotropic liquid crystal physical properties

Thermotropic liquid crystal polymers

Thermotropic liquid crystal polymers LCPs)

Thermotropic liquid crystal polymers TLCPs)

Thermotropic liquid crystal polymers applications

Thermotropic liquid crystal polymers determination

Thermotropic liquid crystal polymers fundamentals

Thermotropic liquid crystal polymers processing

Thermotropic liquid crystalline

Thermotropic liquid crystalline copolyesteramides

Thermotropic liquid crystalline elastomers

Thermotropic liquid crystalline materials

Thermotropic liquid crystalline melt processing

Thermotropic liquid crystalline phase

Thermotropic liquid crystalline phase transition temperatures

Thermotropic liquid crystalline polyarylates

Thermotropic liquid crystalline polyester

Thermotropic liquid crystalline polymer nanocomposites

Thermotropic liquid crystals

Thermotropic liquid crystals LCDs)

Thermotropic liquid crystals Subject

Thermotropic liquid crystals advantages

Thermotropic liquid crystals anisotropic properties

Thermotropic liquid crystals applications

Thermotropic liquid crystals calamitic mesogens

Thermotropic liquid crystals characteristics

Thermotropic liquid crystals chiral nematic phase

Thermotropic liquid crystals classical type

Thermotropic liquid crystals crystal smectic phases

Thermotropic liquid crystals defined

Thermotropic liquid crystals discotic mesogen mesophases

Thermotropic liquid crystals discotic mesogens

Thermotropic liquid crystals discotics

Thermotropic liquid crystals electric field alignment

Thermotropic liquid crystals flow behaviour

Thermotropic liquid crystals formation

Thermotropic liquid crystals isotropic-nematic transition dynamics

Thermotropic liquid crystals long-range order

Thermotropic liquid crystals magnetic field alignment

Thermotropic liquid crystals mechanical alignment

Thermotropic liquid crystals metallomesogens

Thermotropic liquid crystals model systems

Thermotropic liquid crystals nematic phase

Thermotropic liquid crystals nematics

Thermotropic liquid crystals optical anisotropy

Thermotropic liquid crystals orientation states

Thermotropic liquid crystals polymorphism

Thermotropic liquid crystals positional ordering

Thermotropic liquid crystals preparation

Thermotropic liquid crystals principle

Thermotropic liquid crystals problems

Thermotropic liquid crystals properties

Thermotropic liquid crystals rheology

Thermotropic liquid crystals sharpness

Thermotropic liquid crystals smectics

Thermotropic liquid crystals supercooled liquids

Thermotropic liquid crystals translational order

Thermotropic liquid crystals viscosity

Thermotropic liquid-crystal-forming

Thermotropic liquid-crystal-forming molecules, structure

Thermotropic liquid-crystalline polymers TLCP)

Thermotropic liquid-crystalline polymers interest

Thermotropic liquid-crystalline polymers mechanical properties

Thermotropic liquid-crystalline solvents

Thermotropic living polymerization

Thermotropic longitudinal PLCs

Thermotropic main chain LCPs

Thermotropic main-chain LCPs applications

Thermotropic main-chain LCPs mechanical properties

Thermotropic main-chain LCPs morphology

Thermotropic main-chain LCPs properties

Thermotropic main-chain LCPs rheology

Thermotropic main-chain LCPs structure

Thermotropic main-chain liquid

Thermotropic main-chain liquid crystalline polymers

Thermotropic main-chain polyethers based

Thermotropic materials

Thermotropic melts

Thermotropic mesogens

Thermotropic mesogens, cubic phase

Thermotropic mesogens, magnetic properties

Thermotropic mesomorphism

Thermotropic mesophase

Thermotropic mesophase crystal

Thermotropic mesophase ferroelectricity

Thermotropic mesophases

Thermotropic monomeric

Thermotropic nematic phases

Thermotropic nematic phases biaxial

Thermotropic nematic phases columnar

Thermotropic nematic polyesters

Thermotropic phase behavior

Thermotropic phase transitions of pure lipids in excess water

Thermotropic phase, cellulosic

Thermotropic phase, cellulosic mesophases

Thermotropic phases

Thermotropic poly

Thermotropic polyamides

Thermotropic polyarylate

Thermotropic polybibenzoates

Thermotropic polyester

Thermotropic polyesters properties

Thermotropic polyesters solid state physics

Thermotropic polyethers

Thermotropic polymer molecular structures

Thermotropic polymer nematic

Thermotropic polymer phase transitions

Thermotropic polymer shape

Thermotropic polymeric liquid crystals

Thermotropic polymers

Thermotropic polymers comb-shaped

Thermotropic polymers optical properties

Thermotropic polymers polymer blends

Thermotropic polymers structure

Thermotropic polymers, banded textures

Thermotropic polymorphism

Thermotropic properties

Thermotropic quasi-liquid crystals

Thermotropic side chain block copolymers

Thermotropic side-chain LCPs

Thermotropic side-chain LCPs materials

Thermotropic side-chain liquid-crystalline

Thermotropic smectics

Thermotropic solubility

Thermotropic spacers

Thermotropic state

Thermotropic systems

Thermotropic systems, external fields

Thermotropic textures

Thermotropic transitions

Thermotropic transitions definition

Thermotropic, compatibilization with

Thermotropic, definition

Thermotropic, liquid crystalline polyme

Thermotropically mesomorphic polymers

Thermotropics, solvents

Toluenes thermotropic behavior

Transient Shear Flow of Thermotropic Main-Chain LCPs

Transitions in thermotropic liquid crystal polymers

© 2024 chempedia.info