Sanidics: A new class of mesophases, displayed by highly substituted rigid-rod polyesters and polyamides

Ebert, Martina; Herrmann‐Schönherr, Otto; Wendorff, Joachim H.; Ringsdorf, Helmut; Tschirner, Peter

doi:10.1080/02678299008029194

Cited by 62 publications

(68 citation statements)

References 21 publications

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“…In this case, the intermolecular interaction may lead to a three-dimensional layered packing with a smaller unit cell, usually accommodating two chains. 1,3 For segmented LCPs, like P(m,n) 11,12 and PA(n) in this report, we observed a similar trend, but also the establishing of LRO along the chain axis direction in the case of Hp or pseudohexagonal phase (pHp). LRO is probably promoted by the higher chain flexibility, which allows lateral register between chains.…”

Section: Resultssupporting

confidence: 83%

“…It has been shown that the insertion of lateral substituents to the chain backbone of LCPs is a suitable way for lowering the melting temperature and to promote solubility in common organic solvent. [1][2][3][4][5][6][7][8][9] It has also been shown that crosslinking segmented-chain LCPs containing adequately functionalized substituents may lead to liquid crystalline networks (LCN) having thermotropic behavior. 10 We have recently reported on the phase properties of the following set of enantiotropic polymers, namely P (m,n).…”

Section: Introductionmentioning

confidence: 99%

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Segmented liquid crystalline polyesters with allyl group as lateral substituent

Caruso¹,

Iannelli²,

Roviello³

et al. 1998

J. Polym. Sci. B Polym. Phys.

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Section: Resultssupporting

confidence: 83%

Section: Introductionmentioning

confidence: 99%

Segmented liquid crystalline polyesters with allyl group as lateral substituent

Caruso¹,

Iannelli²,

Roviello³

et al. 1998

J. Polym. Sci. B Polym. Phys.

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“…21 The movement of crystalline segments is variably inhibited by the amorphous portion; thus, formation of various segregated structures is often observed from similar materials. The 'crystalline-crystalline' comb polymers, [22][23][24][25] especially those with aromatic main chain polymers, [26][27][28][29] are of interest because packing of the bulky aromatic polymer main chain can be changed by varying the crystallinity of side chains. As the first example, Kevlar, poly(p-phenylene terephthalamide), was functionalized with linear hydrocarbons of 3, 4, 7, 12 and 18 carbon atoms through metalation of poly(p-phenylene terephthalamide) using sodium hydride (degree of substitution (DS) was 86-99%, inherent viscosity (Z inh ) 0.06-0.14), and the packing mode was investigated for the resulting comb polymers, which were all amorphous except for the polymer with C 18 H 37 side chains.…”

Section: Introductionmentioning

confidence: 99%

Direct condensation polymerization of N-alkylated p-aminobenzoic acid and packing of rigid-rod main chains with flexible side chains

Shibasaki

Abe

Sato

et al. 2010

Polym J

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Direct condensation polymerization of N-alkylated p-aminobenzoic acid, in which methyl, propyl, butyl, pentyl, heptyl, octyl and heptadecyl substituents were used as the alkyl group, was performed using hexachloroethane, triphenylphosphine and pyridine as condensation reagents. Pale-yellow N-alkylated poly(p-benzamide) (PABA n ) polymers, where n is the number of carbon atoms of the alkyl side chain, were obtained in 46-87% yields with an inherent viscosity of 0.06-0.65 per 100 ml g À1 (conc. H 2 SO 4 , 30 1C). The structures of PABA n were identified using infrared, nuclear magnetic resonance and elemental analysis. PABA n with long alkyl side chains (n43) showed good solubility in chloroform, as well as conc. H 2 SO 4 and m-cresol. The glass transition temperature (T g ) of PABA n measured by differential scanning calorimetry gradually decreased with an increase in the length of the alkyl group. The endothermic peak corresponding to melting was observed for PABA n with n¼3, 4, 5 and 17 on DSC profiles. The wide-angle powder X-ray scattering of the polymer samples indicated that PABA n polymers with n¼0, 1, 3, 4, 5 and 17 were crystalline polymers. X-ray scattering profiles showed PABA n with n¼3, 4 and 5 crystallized in an orthorhombic lattice, whereas PABA 1 crystallized in a monoclinic lattice. PABA 17 crystallized in hexagonal packing at the long side chain with an interplanar spacing of 4.2 Å .

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“…For biaxial particles the corresponding theoretical parameter, r l , exists but can no longer be rigorously defined by equation (8). However, a crude approximation for the virtual transition temperature of p-Xylene can be made (assuming the same molar volumes).…”

Section: I-i = [$]mentioning

confidence: 99%

²H-NMR Study of Orientational Order in Binary Mixtures: A Nematic Phase of Biaxial Molecules

Hoatson

Goetz

Palffy‐Muhoray³

et al. 1991

Molecular Crystals and Liquid Crystals

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Deuteron Magnetic Resonance (2H-NMR) spectra have been obtained from a binary mixture of 2-fluorenyl-4'-tetradecyloxy benzoate-d, (FLOC,,) and para-Xylene-d,,, (p-Xy), as a function of temperature. The liquid crystal, FLOC,,, is selectively deuterated on the rigid fluorene moiety while the p-Xy is perdeuterated. The quadrupolar splittings, v6, allow the unambiguous determination of the temperature dependence of the orientational order parameters, S,,, and (S,,, -S,,,), of both species, i = 1,2. These results are the first to provide information on the degree and asymmetry of orientational order, of both biaxial molecules, in the uniaxial nematic phase of a binary mixture. A new approach was adopted for analyzing the experimental data which uses a least squares fit of the quadrupolar splittings, v6, to provide the four component order parametersThe experimental results are interpreted using a recently proposed mean field theory of binary mixtures of biaxial molecules. ' In the geometric mean approximation all particles couple to an identical mean field and the parameters of the theory are the ratios of intermolecular interaction strengths of the pure materials. There is good agreement between the predictions of theory and the four component order parameters determined from 2H-NMR experiments, over the entire temperature range studied. Thus this description is capable of predicting the temperature dependence and interrelation of the nematic orientational order parameters for both components of the mixture. Analogous calculations on data from pure FLOC,,Z gives a ratio of interaction strengths consistent with that obtained from the binary mixture. S 2 , , ) .

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Sanidics: A new class of mesophases, displayed by highly substituted rigid-rod polyesters and polyamides

Cited by 62 publications

References 21 publications

Segmented liquid crystalline polyesters with allyl group as lateral substituent

Segmented liquid crystalline polyesters with allyl group as lateral substituent

Direct condensation polymerization of N-alkylated p-aminobenzoic acid and packing of rigid-rod main chains with flexible side chains

²H-NMR Study of Orientational Order in Binary Mixtures: A Nematic Phase of Biaxial Molecules

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Sanidics: A new class of mesophases, displayed by highly substituted rigid-rod polyesters and polyamides

Cited by 62 publications

References 21 publications

Segmented liquid crystalline polyesters with allyl group as lateral substituent

Segmented liquid crystalline polyesters with allyl group as lateral substituent

Direct condensation polymerization of N-alkylated p-aminobenzoic acid and packing of rigid-rod main chains with flexible side chains

2H-NMR Study of Orientational Order in Binary Mixtures: A Nematic Phase of Biaxial Molecules

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²H-NMR Study of Orientational Order in Binary Mixtures: A Nematic Phase of Biaxial Molecules