Synthesis, characterisation and liquid crystalline properties of some Schiff base-ester central linkage involving 2, 6- disubstituted naphthalene ring system

High Performance Polymers

2012

The present work initially deals with the fabrication of a new generation of polyesters (bearing thiophene, azomethine, thiourea and ether moieties) and subsequent blending with polyaniline (PAN) exhibiting extremely valuable nanoblend characteristics. Few poly(azomethine-thiourea-ester)s (PATEs), by the polycondensation of a new diol 4,4 0 -oxydiphenyl bis((E)-1-(4-hydroxobenzylidene)thiourea) with thiophene-2,5-dicarbonyl/terephtaloyl chloride, were synthesized. The polymers obtained were characterized by Fourier-transform infrared, proton-nuclear magnetic resonance, solubility, solution viscosity, gel permeation chromatography, thermogravimetric analysis, differential scanning calorimetry and wide-angle x-ray diffraction. The polymers exhibited high molar mass (77-89 Â 10 3 ) and thermal stability (T 10 528-531 C, glass transition temperature (T g ) 265-268 C). Then the electrically conducting blends, of PAN dispersed in the PATEs matrix, were prepared by mash-blending and melt-blending techniques. Materials obtained by conventional melt-blending approach generated an efficient conductive network compared with those produced by mash blending. Field emission scanning electron microscopy images displayed nanoblend morphology of the melt-blended system, owing to increased physical interactions (hydrogen bonding and p-p stacking) between the two polymers. Moreover, miscible blends of thiophene-based PATE/PAN led to superior conductivity (1.5-2.1 S/cm) and heat stability (T 10 503 C) even at low PAN concentration relative to previous thiophene, azomethine or PAN-based structures.

Section: Resultsmentioning

confidence: 99%

“…Future studies may involve interesting results in view of their application in single-layer organic devices and even more complex organic LEDs. 22,36…”

Section: Discussionmentioning

confidence: 99%

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Nanoblends of novel polyesters with polyaniline: Conductivity and heat-stability studies

High Performance Polymers

2012

“…Future studies may entail attractive consequences regarding their application in single layer organic devices and more complex organic light emitting diodes. 26…”

Section: Discussionmentioning

confidence: 99%

“…Finally, the product obtained by recrystallization (ethyl alcohol) was dried at 80 C for 36 h to give HCBTCANT with 95.1% yield. Elemental analysis for C 26…”

Section: Synthesis Of Hcbtcantmentioning

confidence: 99%

Thermal, morphological, and conductivity profile of pyridine/thiophene-based polyesters and their miscible blends

Journal of Thermoplastic Composite Materials

2013

New Schiff-base polyesters were prepared from a dihydroxy monomer (E)-1-(5-(4-hydroxy-3-chlorobenzylidene)thiocarbamoylaminonaphthyl)-3-(4-hydroxy-3-chlorobenzylidene)thiourea. The processable pyridine or thiophene-based poly(azomethine-ester)s (PAEs) possess high molar mass of 111 Â 10 3 -127 Â 10 3 g mol À1 . The 10% weight loss (521-527 C) and glass transition temperature (287-291 C) depicted high thermal stability. Polyaniline (PAN) doped with dodecylbenzenesulfonic acid (PAN/DBSA), prepared by in situ doping polymerization, was blended in solution/melt with PAEs. Field emission scanning electron microscopy of melt blended PAEs/PAN/DBSA showed nanolevel homogeneity of microstructure accountable for superior electrical conductivity (1.9-2.8 S cm À1 ). The miscible nanoblends also exhibited high heat stability (T 10 ; 500-507 C) and mechanical strength (45.51-48.17 MPa) relative to reported azomethine/PAN-based structures.

New generation of thermally stable and conducting poly(azomethine-ester)s: nano-blend formation with polyaniline

2012

Polym. Int.

A new dihydroxy monomer, (E)-1-(4-(4-(4-hydroxybenzylidene)thiocarbamoylaminobenzyl)phenyl)-3-(4-hydroxybenzylidene)thiourea, was synthesized and polymerized with thiophene-2,5-dicarbonyl/terephthaloyl chloride. The structural characterization of the resulting polymers was carried out using spectral techniques (Fourier transform infrared and 1 H NMR) along with a physical property investigation. Novel polyesters are readily soluble in various amide solvents and possess high molar mass of 112 × 10 3 -133 × 10 3 g mol −1 . The thermal stability was determined via 10% weight loss to be in the range 519-523 • C and the glass transition temperature was 286-289 • C. Electrically conducting poly(azomethine-ester)blend-polyaniline blends were prepared using mash-blending and melt-blending techniques. Materials obtained using the conventional melt-blending approach generated an efficient conductive network compared with those produced by mash blending. Field emission scanning electron microscopy revealed a nano-blend morphology for the melt-blended system owing to increased physical interactions (hydrogen bonding and π -π stacking) between the two constituent polymers. Miscible blends of thiophene-based poly(azomethine-ester)-blend-polyaniline had superior conductivity (1.6-2.5 S cm −1 ) and thermal stability (T 10 = 507 • C) even at low polyaniline concentration relative to reported thiophene/azomethine/polyaniline-based structures. The new thermally stable and conducting nano-blends could be candidates for various applications including optoelectronic devices.