Layer Structure.1.Poly(phenylene-terephthalamide)s Derived from Mono-, Di-, and Tetrakis(alkylthio)terephthalic Acids

Kricheldorf, Hans R.; Domschke, Angelika

doi:10.1021/ma00084a037

Cited by 50 publications

(44 citation statements)

References 6 publications

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“…This curve indicates that the diameter increases linearly with increasing carbon number. The increment ratio was found to saturate around n = 14, suggesting that the n-alkyl chain in the polymer has not an extended trans-planar zigzag chain, but a fold or gauche chain, where odd/even carbon number effects on parameters such as the phase transition temperature are not observed, unlike the case of ordinary liquid crystals 41) . The half line width, DH, of the lowest angle peak of each polymer was also plotted as a function of the carbon number in order to investigate the degree of self-organization order in the columnar polymers (Fig.…”

Section: Formation Of Columnar Polymermentioning

confidence: 94%

Precise synthesis of monosubstituted polyacetylenes using Rh complex catalysts. Control of solid structure and π-conjugation length

Tabata¹,

Sone²,

Sadahiro³

1999

Macromol. Chem. Phys.

218

207

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SUMMARY: Stereospecific polymerization of monosubstituted acetylenes was successfully performed using a Rh complex, [Rh(norbornadiene)Cl] 2 , as a catalyst, and the resulting polyacetylenes were characterized in detail by 1 H NMR, ESR, laser Raman, diffuse reflective UV, and wide-angle X-ray diffraction. The Rh complex was found to yield selectively the cis-transoid isomer even at room temperature in high yields when alcohol or triethylamine was used as the solvent. Additionally, the resulting cis-polyacetylenes were found to form a pseudohexagonal, columnar self-assembly or superstructure. Further compression of the cis-polymers induced cis-trans isomerization even at room temperature under vacuum, breaking rotationally the cis-C2C bonds and, thus, giving p-radicals as the origin of magnetic properties.

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Section: Formation Of Columnar Polymermentioning

confidence: 94%

Precise synthesis of monosubstituted polyacetylenes using Rh complex catalysts. Control of solid structure and π-conjugation length

Tabata¹,

Sone²,

Sadahiro³

1999

Macromol. Chem. Phys.

218

207

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“…15 Another approach employed to increase the solubility of rigid-rod polyamide is by incorporation of the nonlinear moieties such as a bulky noncoplanar groups in the polymer backbone. [16][17][18][19] It is well known that the incorporation of bulky CF 3 into polymers backbone results in an enhanced solubility and optical transparency together with a lowered dielectric constant which is attributed to low polarizability of C-F bond and the increase in free volume. [20][21][22][23] Furthermore it seems that insertion of sulfoxide in the polymer structure enhances the processability, thermal resistance, and solubility of the final polymer.…”

mentioning

confidence: 99%

Synthesis and Properties of Novel Fluorinated Polyamides Based on Noncoplanar Sulfoxide Containing Aromatic Bis(ether amine)

Shockravi¹,

Abouzari‐Lotf

Javadi³

et al. 2009

Polym. J.

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A novel sulfoxide containing bis(ether amine) monomer, 2,2 0 -sulfoxide-bis[4-methyl(2-trifluoromethyl)4-aminophenoxy) phenyl ether] (M2), was synthesized from the halogen displacement of 2-chloro-5-nitrobenzotrifluoride with dibenzosulfoxide (DH) in the presence of potassium carbonate, followed by catalytic reduction of bis(ether nitro) intermediate with Zinc/Ammonium chloride. A series of organic-soluble poly(ether amide)s (PA1-7) bearing sulfoxide and electronwithdrawing trifluoromethyl group were synthesized from bis(ether amine) with various aromatic diacids (1-7) via a direct polycondensation with triphenyl phosphite and pyridine. The resulting polymers had inherent viscosities ranging from 0.35 to 0.90 dL g À1 at a concentration of 0.5 g/dL in N,N-dimethylacetamide (DMAc) solvent at 25 C. All the polymers showed outstanding solubility and could be easily dissolved in amide-type polar aprotic solvents (e.g., N-methyl-2-pyrrolidone (NMP), DMAc, and N,N-dimethylformamide) and even dissolved in less polar solvents (e.g., pyridine, and tetrahydrofuran). Also these polymers could be cast into flexible and tough films from DMAc solutions. The glass-transition temperatures of these poly(sulfoxide ether amide)s were recorded between 160-220 C. 10% weight loss temperatures were recorded in the range of 400-505 C in nitrogen and 380-480 C in air atmosphere.

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“…The yields and properties of the diacids are listed in Tab.1. 2,5-Bis((S)-2-methylbutylthio)terephthaloyl chloride was synthesized as described previously 26) . The yield and the properties of the diacid dichloride are listed in Tab.1.…”

Section: Mono-or Bis((s)-2-methylbutylthio)terephthalic Acidmentioning

confidence: 99%

“…The syntheses of mono-and bis((S)-2-methylbutoxy)-terephthalic acids have been reported previously 26) . They were prepared by alkylation of diethyl trimethylsiloxy-or bis(trimethylsiloxy)terephthalates.…”

Section: Synthesesmentioning

confidence: 99%

Layer structures, 13. Chiral sanidic polyesters derived from 2,5-bis(alkylthio)terephthalic acids

Kricheldorf¹,

Wulff

Wutz

1999

Macromol. Chem. Phys.

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SUMMARY: Two chiral terephthalic acids were synthesized from (S)-2-methylbutane-1-thiol and bromoterephthalic acid or 2,5-dibromoterephthalic acid. A series of chiral polyesters was then prepared by polycondensation of silylated 4,49-dihydroxybiphenyl and mixtures of 2,5-bis(dodecylthio)terephthaloyl chloride and 2,5-bis((S)-2-methylbutylthio)terephthaloyl chloride. The copolyesters were characterized by elemental analyses, viscosity, DSC and X-ray measurements, and optical microscopy. Depending on the reaction conditions low and high molecular weights were obtained. In addition to a solid sanidic phase these polyesters form a chiral sanidic LC-phase and a chiral nematic LC-phase. However, in contrast to a normal cholesteric melt, these polyesters did not form a Grandjean texture but display the unusual "sausage texture".

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Layer Structure.1.Poly(phenylene-terephthalamide)s Derived from Mono-, Di-, and Tetrakis(alkylthio)terephthalic Acids

Cited by 50 publications

References 6 publications

Precise synthesis of monosubstituted polyacetylenes using Rh complex catalysts. Control of solid structure and π-conjugation length

Precise synthesis of monosubstituted polyacetylenes using Rh complex catalysts. Control of solid structure and π-conjugation length

Synthesis and Properties of Novel Fluorinated Polyamides Based on Noncoplanar Sulfoxide Containing Aromatic Bis(ether amine)

Layer structures, 13. Chiral sanidic polyesters derived from 2,5-bis(alkylthio)terephthalic acids

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