New organosoluble aromatic poly(esterimide)s containing pendent pentadecyl chains

A new diimide dicarboxylic acid, namely 2,2′-(4-pentadecyl-1,3-phenylene)bis(1,3-dioxoisoindoline-5-carboxylic acid), containing preformed imide rings and pentadecyl chain, was synthesized by the reaction of 4-pentadecylbenzene-1,3-diamine with trimellitic anhydride. A series of new aromatic poly(esterimide)s (PEIs) was synthesized using diphenylchlorophosphate-activated direct polycondensation of 2,2′-(4-pentadecyl-1,3-phenylene)bis(1,3-dioxoisoindoline-5-carboxylic acid), with five commercially available bisphenols, namely 4,4′-isopropylidenediphenol (I), 4,4′-(hexafluoroisopropylidene)diphenol (II), 4,4′-oxydiphenol (III), 4,4′-biphenol (IV), and 4,4′-(9-fluorenylidene)diphenol (V) in the presence of pyridine and lithium chloride. Inherent viscosities of PEIs were in the range 0.54–0.83 dL g−1 in chloroform (CHCl3) at 30 ± 0.1°C. PEIs containing pendent pentadecyl chains were soluble in organic solvents such as CHCl3, m-cresol, N, N-dimethylacetamide, 1-methyl-2-pyrrolidinone, pyridine, and nitrobenzene. Tough, transparent, and flexible films of PEIs could be cast from their CHCl3 solutions. PEIs exhibited glass transition temperature in the range 145–198°C. The temperature at 10% weight loss of PEIs, determined by thermogravimetric analysis under the nitrogen atmosphere, was in the range of 450–470°C indicating good thermal stability.

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

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′-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 × 103) and thermal stability ( T10 528–531°C, glass transition temperature ( Tg) 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 π–π 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 ( T10 503°C) even at low PAN concentration relative to previous thiophene, azomethine or PAN-based structures.

High performance new heteroaromatic poly(thiourea-imide-ester)s

A new dihydroxy monomer, 1-(2-hydroxypyridin-3-yl)-3-(2-(2-hydroxypyridin-3-yl)-1,3-dioxo-isoindoline-5-carbonyl)thiourea, with preformed trimellitic anhydride chloride-derived imide ring, pyridine and C=S moieties was synthesized. This compound was exploited to prepare three heteroaromatic poly(thiourea-imide-ester)s (PTIEs) by polycondensation with various diacid chlorides. Structural analysis of polymers was carried out by Fourier transformation infrared and nuclear magnetic resonance spectroscopy. PTIEs were readily soluble in polar solvents such as N, N-dimethylacetamide, dimethylformamide, dimethyl sulfoxide and N-methylpyrrolidone. Inherent viscosity and gel permeation chromatography measurements revealed high molar mass (140 × 102 to 101 × 102). One of the polymers showed crystalline behavior according to x-ray diffraction. Thermogravimetric analysis and differential scanning calorimetry were adopted for the thermal analysis of the polymers. Novel aromatic PTIEs possess high weight loss temperature ( T10) in the range 524–536°C and glass transition temperature of about 223–230°C.